Robert Grosseteste (ca. 1168–1253), Bishop of Lincoln from 1235to 1253, was one of the most prominent and remarkable figures inthirteenth-century English intellectual life. A philosopher,theologian, and student of nature, Grosseteste also translated andcommented on works by Aristotle and Greek patristic thinkers. Heplayed a pivotal role in the development of Aristotelianism, beingamong the first Latin philosophers to incorporate theories of Avicennaand Averroes, while also drawing heavily from Augustine. Grossetestecrafted a highly original and imaginative account of the creation andfundamental structure of the physical world, grounded in the conceptof the action of light. His writings encompass numerous treatises onnatural phenomena, as well as works in philosophy and theology. In hisecclesiastical capacity as bishop, Grosseteste actively addressedpastoral care issues, striving to rectify abuses within the church,and in his later years, he even traced some of these issues to thepapacy itself. Revered by his contemporaries and later scholars atOxford, Grosseteste has been often celebrated as an inspiration toscientific developments in fourteenth-century Britain.

• 1. Life
• 2. Works
• 3. Sources
• 4. The Metaphysics of Light
• 5. Infinity, Continuity, and Measurement
• 6. Creation, Eternity, Time, and Being
• 7. Divine Foreknowledge and Human Freedom
• 8. Modality and God’s Power
• 9. Free Decision and Freedom of the Will
• 10. Exemplarism, Truth, and Illumination
  • 10.1 Exemplarism
  • 10.2 Truth
  • 10.3 Illumination
• 11. Scientific Method
• 12. Influence
• Bibliography
  • Bibliographies
  • Biographical Studies
  • Primary Texts in Latin
  • Primary Texts in English Translation
  • Secondary Literature
• Academic Tools
• Other Internet Resources
• Related Entries

1. Life

Grosseteste was born in the county of Suffolk in England, possiblyaround 1168 (Callus 1955). Around 1195, in a letter to the Bishop ofHereford, William de Vere, Gerald of Wales commends Grosseteste forhis wide reading and skill in business and legal affairs, medicine,and the liberal arts, and remarks on his exceptional standards ofconduct. Grosseteste appears as a papal judge-delegate in Litchfielddiocese before 1216 and in Hereford diocese between 1213 and 1216,acting with Hugh Foliot, Archdeacon of Shropshire. For at least partof the years 1208 to 1213, when England was under papal interdict,Grosseteste was in France, for in a death-bed conversation reported bythe chronicler Matthew Paris he recalls having seen and heardpreaching in France by Eustace of Flay, James of Vitry, Robert ofCourson and the exiled Archbishop Steven Langton. In 1225, while stilla deacon, Grosseteste was presented by the Bishop of Lincoln, Hugh ofWells, to the living of Abbotsley. In 1229 he was made Archdeacon ofLeicester and presented with a prebend in Lincoln Cathedral.

Scholars have proposed various reconstructions of Grosseteste’slife between 1200 and 1230. The debate revolves around his activitiesbefore moving to France, during his time in France, and upon hisreturn to England. Regarding his pre-France period, Daniel Callus(1945, 1955, with Crombie 1953 and McEvoy 1982, 2000 in substantialagreement) posits that Grosseteste may have taught arts at Oxford. Incontrast, Sir Richard Southern (1986) emphasizes that Grossetestelikely held an administrative position with occasional teachingduties. The disagreement continues into Grosseteste’s time inFrance. Callus suggests that Grosseteste moved to France in 1209following a town-and-gown dispute in Oxford and studied theologythere. Southern rejects this view, maintaining that Grossetesterelocated due to the papal interdict of England, and during thisperiod, he did not engage in theological studies.

The complexity intensifies when examining Grosseteste’sactivities upon his return from France. Callus argues that Grossetestelikely returned from France in 1214, becoming Oxford’s firstchancellor in function, if not in title. Southern instead suggeststhat Grosseteste’s permanent association with Oxford startedafter 1225 when, having received the prebend of Abbotsley, Grossetesteprobably became a priest and began lecturing in theology. JosephGoering (1995), in turn, proposes that Grosseteste returned to Englandafter 1215, working as a master of arts in Oxford throughout the1220s. During that decade, Grosseteste may have returned to Paris fortheological studies, possibly around 1225, after receiving theAbbotsley prebend. According to James Ginther (2000), Grossetestebecame regent master of theology around 1229/30, coinciding with hisrole as a lecturer for the Oxford Franciscans. Nevertheless, BrettSmith (2018: n. 34) expresses doubts about Ginther’s claims.

The reconstruction of the later period of Grosseteste’s lifebenefits from additional historical data. In 1224, the Franciscansarrived at Oxford, and their Minister Provincial, Agnellus of Pisa,established their first school. Agnellus requested Grosseteste tolecture to them and, in 1229/30, Grosseteste began a formalassociation with the Franciscans at Oxford as their first lecturer(see Panti 2017a). In 1235, he was elected Bishop of Lincoln, aresponsibility that clashed with his teaching duties, prompting him torelinquish them. However, Grosseteste maintained close relations withthe Franciscans throughout his life.

In 1231, following a recovery from a severe illness, Grossetesteresigned from all his sources of revenue, except his prebend inLincoln Cathedral. He proceeded to compose a series of significanttheological works, with theHexaæmeron being the mostnotable. Starting from the early 1230s (see Dionisotti 1988),Grosseteste began studying Greek. Assisted by individuals proficientin the language, he undertook crucial translation projects, includingworks by John of Damascus, Pseudo-Dionysius (accompanied by his ownoriginal commentary), and Aristotle. The list includes the firstextant complete Latin translation of theNicomachean Ethicsto circulate in the Latin West (see Beullens 2023b), along withtranslations of numerous Greek commentary materials (see Panti 2023).Grosseteste also translated substantial parts of Aristotle’sDe caelo and Simplicius’s commentary on it, apparentlyin the late stages of his life.

In the 1240s, the conflict between the emperor and the pope led to theFirst Council of Lyon in 1245, in which Grosseteste participated. Hereturned to the papal court in Lyon in 1250, expressing to the popehis concerns about the failings of the church and its deviation fromits pastoral mission. In 1253, the last year of his life, Grossetestewrote an impassioned letter (#128) to the pope, refusing to obey thepontifical instructions to confer a benefice on one of thepope’s nephews, whom he deemed unfit for pastoral care.

Grosseteste passed away on October 8–9, 1253. Althoughremembered by his contemporaries as a saintly man, three attempts tocanonize him (the last in 1307) ultimately failed.

2. Works

Grosseteste’s extensive and diverse body of writings encompassesworks of various genres and domains, including scientific andphilosophical treatises, commentaries on Aristotle’s andbiblical works, theological writings, sermon collections, letters, anda substantial collection of short theological pieces known as theDicta. Additionally, Grosseteste ventured into Anglo-Normanpoetry. His works of philosophical interest can be classified asfollows:

• Scientific treatises. Grosseteste’s earlyscientific works, likely composed in the 1210s and 1220s, include
  • On the Liberal Arts (De artibusliberalibus),
  • On the Generation of Sounds (De generationesonorum), and
  • On the Sphere (De sphaera).
  Expanding his scientific inquiry, Grosseteste later wrote onspecific natural problems in works like
  • On Comets (De cometis),
  • On Lines, Angles, and Figures (De lineis, angulis etfiguris),
  • On the Nature of Places (De naturalocorum),
  • On the Rainbow (De iride),
  • On Color (De colore),
  • On Local Differences (De differentiislocalibus), and
  • On the Movement of the Supercelestial Bodies (De motusupercaelestium)
  (for an outline, see Dales 1961 and Panti 2001). Further worksascribed to Grosseteste, namely,
  • On the Heat of the Sun (De calore solis),
  • On the Tides (De fluxu et refluxu maris),
  • On the Generation of the Stars (De generationestellarum), and
  • On the Impressions of the Air (De impressionibusaeris)
  are likely inauthentic, with the first two probably written byAdam of Exeter (Panti 2013b).
• Philosophical treatises. Grosseteste composedseveral short philosophical works, the most renowned of which isOn Light (De luce). Another noteworthy piece,OnBodily Movement and Light (De motu corporali et luce)shares a close thematic connection withOn Light. In additionto these, Grosseteste authored several treatises, including
  • On Potency and Act (De potentia et actu),
  • On the Halt of Causes (De statu causarum),
  • On the Subsistence of a Thing (De subsistentiarei),
  • On the Truth of the Proposition (De veritatepropositionis), and
  • On the Finitude of Movement and Time (De finitatemotus et temporis).
• Commentaries on Aristotle. Grosseteste wrotecommentaries on two Aristotelian works, namely, thePosteriorAnalytics and thePhysics, which are among the earliestsurviving commentaries on these works in the Latin West. Thecommentary on thePosterior Analytics,likely written in the 1220s, is an important sourcefor Grosseteste’s epistemological views. The commentary on thePhysics appears to have been assembled by a later editor(s)from notes Grosseteste had written in his copy of thePhysicsto serve as the basis for a more structured commentary like that onthePosterior Analytics. Although incomplete, these notescomprise a substantial and coherent work, the bulk of which was alsoprobably written in the 1220s, with some later additions based onAverroes’s long commentary on thePhysics (see Lewis2003). Extant manuscripts also include a paraphrase of thePriorAnalytics, attributed to and possibly genuine to Grosseteste,along with a commentary on theSophistici Elenchi and asecond commentary on thePhysics which, however, appear to beinauthentic.
• Philosophical-theological works. Grossetestedelved into the intricate intersection of philosophical andtheological inquiries through a series of works. Among them isOnFree Decision (De libero arbitrio), a relatively lengthyexploration in two versions that confronts arguments challenging theexistence of free decision (liberum arbitrium). This work iscomplemented by shorter treatises such asOn Truth (Deveritate) andOn God’s Knowledge (De scientiaDei), likely composed in the late 1220s or early 1230s. Anothernotable contribution is found inOn the Order of the Emanation ofCaused Things from God (De ordine emamandi causatorum aDeo), where Grosseteste challenges the notion that an eternalbeing can only create eternal creatures. In a lengthy letter addressedto Adam Rufus (Adam of Exeter), Grosseteste explores the idea that Godis the form of all things, delving into the relationship between bodyand soul and the celestial abode of angels. In the manuscripts, thisletter is often divided into two distinct works,On the UniqueForm of all Things (De unica forma omnium) andOnthe Intelligences (De intelligentiis).
• Theological works of philosophical interest. Someof Grosseteste’s theological works carry notable philosophicalsignificance. InOn the Cessation of the Ceremonial Laws(De cessatione legalium), Grosseteste argues that theIncarnation would have occurred even without the Fall, and touches onthe nature of human happiness and natural law.On the TenCommandments (De decem mandatis) offers glimpses intoGrosseteste’s ethical thinking, while his theologicalmasterpiece, theHexaæmeron, thoroughly explores theissue of the eternity of the world. Philosophically relevant materialis also present in theDicta, some of Grosseteste’slater sermons (most notably the sermonEcclesia sanctacelebrat, where he outlines his account of human nature), and hiscommentaries on the Pseudo-Dionysius

3. Sources

Being among the first Latin philosophers to systematically engage withAristotle, Grosseteste utilized a vast array of diverse sources. Amongthem, a crucial role is played by philosophers from the Aristoteliantradition and, crucially, the works of Aristotle, Avicenna, andAverroes, which Grosseteste pioneered (Gauthier 1982). These sourcesare complemented by theological works from both the Western tradition(particularly Augustine, but also Boethius, Anselm, and Bernard ofClairvaux) and, later in his life, the Eastern tradition (especiallyJohn of Damascus, Basil, and Pseudo-Dionysius). Further sets ofsources used by Grosseteste encompass scientific works written ortranslated into Latin, as well as Roman literature (especially Ciceroand Seneca).

Grosseteste’sTabula (Rosemann 1995) offers an unusualinsight into these sources. This work is a topical concordance inwhich Grosseteste lists readings on a wide range of topics oftheological and philosophical interest. For each topic, Grossetesteassociated a sign, allowing him quick access to the material inquestion.

While Grosseteste was undoubtedly influenced to some extent by hiscontemporaries, his works display little concern to engage in debateswith them, contrasting with the practices of his peers in Paris. Thismay reflect the provincial origin of Grosseteste’s works and/ora conservative preference to engage with the ideas of the greatthinkers of the philosophical and theological traditions.

4. The Metaphysics of Light

The concept of light holds a prominent position in Grosseteste’swritings, extending from his natural treatises to his ontological,theological, and epistemological theories. Philosophically, hisutilization of the concept of light in explaining the fundamentalstructure and origin of the physical universe stands out as profoundlyimportant and original. While he expounds on this theory mostcomprehensively inOn Light, traces of it also surface in hiscommentaries on thePosterior Analytics and thePhysics, inOn Bodily Movement and Light, and in hiscommentary onEcclesiasticus 43: 1–5, also known asOn the Operations of the Sun.

Grosseteste’s metaphysics of light is anchored in hishylomorphic account of the constitution of bodies. According to him,all natural bodies are compounds of prime matter and substantial form.Likely influenced by either Avicenna, Avicebron, or both (see Polloni2021a, Lewis 2023), Grosseteste posits that all bodies possess abodily form (forma corporalis) extending prime matter intothree dimensions. This assertion suggests Grosseteste’sadherence to formal pluralism—a theory positing that physicalhylomorphic compounds have more than one substantial form alongsideprime matter (see Polloni 2021a). For example, inOn Light,Grosseteste maintains that the firmament (i.e., the outermost heavenlysphere) is the simplest body, consisting solely of prime matter andthe first form (i.e., the bodily form). However, in his commentary onthePhysics, Grosseteste discusses the element fire,attributing to it, in addition to the first form, the substantial formof fire.

The most original aspect of Grosseteste’s account, however, liesin his identification of the bodily form with light (lux).On Light begins with an argument supporting thisidentification. Grosseteste posits that the first form and primematter are inherently simple substances. Yet, the nature of bodinessnecessitates the extension of prime matter into three dimensions,resulting in a quantified body. A simple form without dimension couldonly achieve this effect if it instantaneously multiplied and diffuseditself in all directions, thereby extending prime matter along withits diffusion. These characteristics align with those of light, whichis inherently self-multiplicative and self-diffusive—where asphere of light is instantaneously generated from a point of light.Hence, Grosseteste concludes that light is indeed the first form (seePanti 2012).

Based on this theory, Grosseteste developed a cosmogony and cosmology.According to him, God created the first form (i.e., light) in primematter, both being indivisible and simple. Grosseteste argues thatfinite multiplication of a simple cannot result in an item with size(quantum). However, he posits that infinite multiplication ofa simple can generate a finitequantum. Consequently, throughthe infinite multiplication of the first form in prime matter, theextended bodies of the physical universe were produced. To accommodatebodies of different sizes, Grosseteste suggests the existence ofinfinities of different sizes (see section 5 below) standing invarious numerical and non-numerical ratios to each other.Therefore,

light, by the infinite multiplication of itself, extends matter intolarger and smaller finite dimensions that stand to one another in allratios, numerical and non-numerical. (Lewis 2013: 241–242)

Grosseteste utilizes the concept of light to explain the genesis ofthe Aristotelian cosmos—a system of nested celestial spheressurrounding the four sublunary or elemental spheres. The infiniteself-multiplication of the initial point of light extended primematter into a spherical form, as light inherently diffuses itselfspherically. The outermost parts of the matter in the generated sphereare maximally extended and rarefied, forming the outermost sphere,known as the firmament.

Because light is essentially self-multiplicative, the light in thisoutermost sphere continued to multiply itself, now inwards toward thecenter from all parts of the outermost sphere, having diffused outwardas far as possible. As light, being a substantial form, cannot existapart from matter, this inwardly directed light brought with it whatGrosseteste calls the spirituality of the matter of the outermostsphere, thelumen, a body comprising light and thespirituality of this matter, which proceeded inwards.

Moving inwards,lumen concentrated the matter below theoutermost sphere, leaving a second sphere below it, comprised of amatter whose parts are as rarefied as possible. This sphere in turngeneratedlumen which, moving inwards, further concentratedthe matter below it and rarefied the outermost parts of this matter toproduce the third sphere. This process repeats, generating the ninecelestial spheres. Each sphere is composed of the matter whose partswere incapable of further rarefaction.

The lowest celestial sphere, the lunar sphere, also generatedlumen, which moved inwards and further concentrated thematter below this sphere. However, as thislumen lackedsufficient power to fully disperse the outermost parts of the matterbelow the lunar sphere, it resulted in a sphere comprised ofincompletely dispersed matter—the sphere of fire. Following thesame process, the production of the three subsequent mundane spheres(the spheres of air, water, and earth) ensued.

Due to the incomplete dispersion of matter in these four elementalspheres, they retained the capacity for concentration and dispersion.This characteristic distinguishes the elemental spheres from theircelestial counterparts, making them susceptible to alteration, growth,and generation and corruption.

Grosseteste also incorporates this theory of light into hisexplanation of the nature of heavenly movements. He posits thatheavenly bodies are perfect because thelumen within them isincapable of rarefaction or condensation and, accordingly, they canonly move circularly. As a result, it cannot influence the parts oftheir matter to incline upward (for rarefaction) or downward (forcondensation). In contrast, the elements can be rarefied andcondensed, allowing them to incline thelumen withinthemselves away from the center of the universe for rarefaction ortoward the center for condensation. This explains their naturalcapacity to move upward and downward.

Although the metaphysics of light deviates fundamentally fromAristotelian principles, Grosseteste evidently sought to employ it asan explanatory framework for various features of the Aristoteliancosmos—such as the nested spheres and the distinction betweenthe movement of celestial and sublunary bodies. In his commentary onthePhysics, Grosseteste interprets fundamental ideas inAristotle’s natural philosophy through the lens of themetaphysics of light. He explains Aristotle’s theory of potencyby emphasizing the replicability of form, claiming that every bodilyspecies comes into existence through “the greater or lesserreplication of the simple first bodily form”, which is light(Dales 1963a: 17).

Similarly, Grosseteste interprets the three Aristotelian principles ofnature—matter, form, and privation—as prime matter, thefirst form/light, and the impurity of light in things, respectively.InOn Bodily Movement and Light, he equates nature, conceivedby Aristotle as an internal source of movement and rest, with thefirst form/light. This first form, acting as a “multiplicativeforce”, becomes the catalyst for various types of bodily changes(see Polloni 2021b).

5. Infinity, Continuity, and Measurement

Grosseteste, likely the first in the Latin West to propose a doctrineof unequal infinities, asserts inOn Light that there areinfinite numbers that differ in size (see Lewis 2013: 241). Accordingto him, infinite numbers can stand to one another not only in everynumerical ratio but also in every non-numerical ratio (Grosseteste hasin mind the ratio of the infinite numbers of points contained inincommensurable lines). He believes that lines and other continuacontain various-sized infinities of dimensionless, simplepoints or indivisibles and they areparts of lines: for him,continua are made of indivisibles. Grosseteste acknowledges thatAristotle seems to reject this view and hold that magnitudes only havemagnitudes as their parts, but he claims inOn Light that theterm “part” has a range of meanings depending on whichmathematical relationship of parts to wholes is in question.Aristotle, he asserts, means by “part” in connection withcontinua andaliquot part and is concerned only to denythat continua are composed of indivisibles asaliquot parts.But this denial does not entail that indivisibles are not partsstanding in a different mathematical relationship to the wholes towhich they belong.On Light maintains that a point is a partof a line in the sense that it is in a line “an infinite numberof times, and does not diminish the line when subtracted from it afinite number of times” (Lewis 2013: 242; see Panti 2017b).Grosseteste says little about the ordering of indivisibles in continuabut mentions without criticism Aristotle’s view thatindivisibles in continua must be densely or “mediately”ordered, so that between any two is yet another, a view attributed tohim by Albert the Great and Thomas Bradwardine (see Lewis 2005).

Grosseteste’s theory of unequal infinities served as the basisof a theory of how God measured the world he created. Grossetestetakes up measurement in his commentary on thePhysics (Dales1963a: 90–95). He points out that human measurement of timeinvolves taking some recurring movement—say, the daily movementof the heaven—and stipulating its duration to be a unit ofmeasurement. In the same way, the magnitude of a body is taken as aunit of the measurement of spatial magnitude. Measurement of thissort, Grosseteste holds, is inherently relative in nature. To say thatan event lasts for a day, for example, is simply to relate itsduration to the duration of the movement of the heavens. Yet Godmeasures things differently. God’s creative activity requireshim to create bodies with a definite magnitude and movements with adefinite duration, and this requires that there be a non-relativemeasure intrinsic to magnitudes and durations. According toGrosseteste, this measure is provided by the different-sizedinfinities of indivisibles comprising spatial and temporal magnitudes.Grosseteste points out in his commentary on thePhysics thatwere only a single line to exist, it would not be possible for us tomeasure its magnitude, and yet God could do so by counting theinfinite number of points that comprise its magnitude. Only God canmeasure in this way, for only to him is the infinite finite.

6. Creation, Eternity, Time, and Being

Grosseteste staunchly embraced the Christian belief in the temporalcreation of the world and asserted that the world’s beginningcould be demonstrated, as suggested by certain arguments inHexaæmeron 1.9.7 His most significant contribution tothe medieval debate on the world’s origin was his interpretationand rebuttal of Aristotle’s arguments of the eternity of theworld inPhysics VIII (see Dales 1986). Grosseteste divergedon this matter from some of his early thirteenth-centurycontemporaries, like Alexander of Hales, who believed Aristotle didnot intend to deny the world’s beginning but only that it had anatural beginning. In theHexaæmeron,Grosseteste admonishes those who adopt such an interpretation,cautioning them “not deceive themselves and pointlessly try tomake a Catholic of Aristotle” (Dales & Gieben 1982: 61).

In both hisHexaæmeron and the closely related treatiseOn the Finitude of Movement and Time, Grosseteste engageswith Aristotle’s arguments for a beginningless world. Hecontends that Aristotle’s errors stem from a failure to fullycomprehend simple eternity. While Grosseteste acknowledges thatAristotle and other philosophers successfully demonstrated theexistence of an unchangeable, non-temporal God and possessed someunderstanding of simple eternity, their incomplete understanding ofsimple eternity meant that they did not really understand what theyproved. According to Grosseteste, this deficiency in understanding canbe attributed to a disordering of theiraffectus or will,rather than theiraspectus or reason. This distinction,possibly derived from Augustine, is a distinctive feature ofGrosseteste’s philosophy (see Smith 2018). InGrosseteste’s view, genuine understanding demands directingone’s will or desire away from the sensory world towards theunchanging eternal realm. Aristotle and his contemporaries,preoccupied with the sensory world, fell short of achieving trueunderstanding.

Grosseteste, like Augustine, posits the concept of ‘simpleeternity’ as the non-temporal mode of existence enjoyed by God.He argues that Aristotle’s claims about the eternity of theworld falter due to a failure to grasp the non-temporal value of thenotions of “before” and “after” when appliedto eternity. Grosseteste contends that Aristotle, in two of hisarguments, wrongly assumes that a first movement necessitates apreceding potency and, therefore, time: for this reason, the firstmovement would not be ‘first’ since time requires movementand potencies are actualized through movement. Grosseteste refutesthis by asserting that, in the consideration of the firstmovement’s existence “after” not existing and itspotency to exist “before” existing, the notions of“before” and “after” are to be taken in anon-temporal sense, within God’s eternity and considering thatthe actualization of this potency involves no movement or change inGod. Addressing Aristotle’s third argument against a firstinstant and his claim that an instant is a link between past andfuture, Grosseteste argues that this view appeals only to thosealready committed to the eternity of time and change.

Grosseteste argues that comprehending eternity is crucial forunderstanding time. In his commentary on thePhysics, hecriticizes Aristotle’s view of time as a number of change,deeming it superficial and insufficient for capturing time’strue essence beyond the realm of natural philosophy. Yet Grossetestealso disagrees with Augustine’s subjectivist conception of timeand aims for an objective understanding of the true essence oftime.

For Grosseteste, time is defined as “the privation of theat-once of eternity from the totality of being” (Dales1963a: 96). This implies that, for time to exist, there must existentities whose existence is not instantaneously eternal (theat-once of eternity). Eternity is like a sort of fixed pointsubject to a continuous succession of the adherences of instantaneousbits of the totality of existence, one bit adhering to eternity onlycontinuously to be replaced by another. This continuous replacementconstitutes the flow of time. Grosseteste defines the instant (the“now”) as the adherence of being to theat-onceof eternity and, accordingly, past and future are also defined inrelation to this adherence. He acknowledges potential circularity inhis tense usage but asks for understanding due to the challenge ofmaking these concepts understandable (Dales 1963a: 98).

Grosseteste’s concept of time seems intricately connected to hisunderstanding of existence, as elucidated in his commentaries on thePosterior Analytics and thePhysics, as well as inOn Truth (Rossi 1981: 290–291; Dales 1963a: 7; Baur1912: 141; see also Lewis 2009). According to Grosseteste, theexistence of a created thingis its dependence on God.Grosseteste appears to equate this relation of dependence with therelation of adherence to theat-once of eternity (see Dales1963a: 96–97). However, it is noteworthy that he does not seemto recognize the distinction between the relata involved in therelation of adherence in his time theory and the relation ofdependence in his account of existence. In the account of time, it isan instantaneous bit of a thing’sexistence thatadheres, while in his account of existence, it is the thing itselfthat is dependent, treating existence as a relation rather than theterm of a relation.

7. Divine Foreknowledge and Human Freedom

Grosseteste’sOn Free Decision stands as one of hismost significant works, with its first half primarily addressing thechallenge of reconciling God’s foreknowledge with human freedom.While the discussion delves into Grosseteste’s noteworthy theoryof modality, its significance also lies in the argument he presentsregarding the incompatibility of God’s knowledge of the futureand future contingency. Noticeably, Grosseteste distinguishes hisapproach from the perspectives offered by Boethius and Anselm in theirearlier discussions of the same issue.

Grosseteste presents the argument as follows:

Everything known by God is or was or will be;a is known byGod (leta be a future contingent); soa is or wasor will be. Buta neither is nor was; so it will be. Each ofthe premises is clearly necessary, as is the inference. So theconclusion is not just true but also necessary, for only what isnecessary follows from things that are necessary. (Lewis 2017:111)

A sound argument without modal premises concludes that an event willoccur. Since its premises are necessary, by the principle thatentailment transmits necessity from premises to conclusion, itsconclusion is necessary too. Grosseteste focuses on premisesformulated in terms of God’s knowledge, but he clearly thinksthat a range of arguments having the same form can be constructed,employing in their initial part also premises formulated in terms ofprophecy or even past-tensed truths of the form “It was the casethatA will exist”.

Grosseteste’s reliance on the principle that entailmenttransmits necessity from the premises to the conclusions of a validinference is a noteworthy aspect of the argument he explores. Despitethe challenges posed in terms of how contingency seems to follow fromnecessity, Grosseteste ultimately maintains the validity of theprinciple, affirming that syllogistic inference ensures thetransmission of necessity from necessary antecedents to conclusions(see Lewis 2017: 139). Grosseteste acknowledges the soundness ofarguments proving the necessity of true propositions about future actsbut challenges the inference that such necessity implies a lack offreedom in those acts. He argues that the type of necessity involvedin such arguments is compatible with freedom. According toGrosseteste, the incompatibility with freedom arises only with adifferent kind of necessity. Arguments relying on this alternativenecessity fail as their premises and conclusions are contingent in thecorrelative sense of contingency.

Grosseteste’s solution to the conflict between divineforeknowledge and free decision includes two key points. First, heclaims that there is a distinct family of modal notions in respect ofwhich future events and true propositions about them may becontingent. Second, he argues that freedom necessitates only thisparticular type of contingency. While he provides limited support forthe latter claim, his introduction of a distinct family of modalnotions is noteworthy and marks a crucial stage in the development ofmodal theory.

8. Modality and God’s Power

When Grosseteste wroteOn Free Decision, modal concepts weretypically understood in terms of the notion of change and,consequently, time. Grosseteste speaks of a necessary proposition, inthis context, as one that is invariably true and incapable of becomingfalse—its truth cannotcease to be. In turn, acontingent proposition can change its truth value. A possibleproposition, if false, can become true, while an impossibleproposition is inherently false and cannot become true. Conceptions ofmodality along these lines were sometimes described asperaccidens conceptions since, in many cases, a proposition’smodal status could change with the passage of time. Its modal statushappens to or is incidental to it (accidit). For instance,“Caesar crossed the Rubicon” was once false and notnecessary but became true and necessary—incapable of becomingfalse—after Caesar crossed the Rubicon. True propositions aboutthe past served as standard examples of propositions necessary in thesense that their truth cannot cease.

Grosseteste argues that true propositions about the present may wellbe contingent on this understanding of contingency, as they can becomefalse. However, he holds that all true propositions about the futureare necessary. One might question this stance, given instances where atrue proposition about the future becomes false after the predictedevent occurs. Yet, upon closer examination, Grosseteste contends thattrue propositions about the future are necessary because they cannotbecome falseprior to the realization of the anticipatedstate of affairs. He has a limited unchangeability of truth inmind.

Grosseteste does not reject this conception ofper accidensmodalities. Instead, he introduces another family of modal notionsunrelated to considerations of time or change—an array ofnon-temporal modal notions. He argues that many true propositionsabout the future, including those about future free acts, fall underthe sense of contingency within this modal family. The latter alsoincludes true propositions about God’s knowledge of those acts,past prophecies, or statements affirming that it was the case that theacts would occur. Traces of similar ideas can be found, althoughimplicitly, in some of his predecessors, like Peter Lombard,whom Grosseteste cites. However, unlike Grosseteste, they had notdelved into a detailedtheory of modality severed fromconsiderations of time and change (except for Peter Abelard, with somecaveats). Later thinkers like Duns Scotus expanded on the concept ofnon-temporal modality with even more detail, sharing elements found inGrosseteste’s account and possibly influenced by it (see Lewis1996).

The central idea guiding Grosseteste’s approach to a notion ofnon-temporal contingency is that even if a proposition, such as“Antichrist will exist” (his standard example of a true,future contingent proposition), is true now and cannot become falseuntil Antichrist comes into existence, the world might neverthelesshave been such that “Antichrist will exist” was nevertrue. A present-day thinker might articulate this idea in terms ofalternative possible worlds, but Grosseteste expresses it in terms ofthe notion of a proposition’s eternal power or capacity fortruth or falsity without a beginning, grounding such powers ultimatelyin God’s eternal power to know or will propositions.

Grosseteste’s discussion of non-temporal modalities and theirrelation to God’s power is most fully set out in the earlierrecension ofOn Free Decision. Focusing on necessity, hewrites that

something is called necessary in that it has no capacity, either notto be, or not to have been, or not to be going to be. [The dictum]“that two and three are five” is necessary in this sense,because it has no capacity not to be true in the present, or in thefuture, or in the past, or ever, be it with or without a beginning.(Lewis 2017: 39,41)

Grosseteste goes on to describe the corresponding notion ofcontingency as a matter of a proposition’s having “acapacity for being true and being false without a beginning”.What is necessary in this sense utterly lacks a power to be false.What is contingent, in the corresponding sense, could have had fromthe beginning a different truth-value, though it may well lack a powerto change its truth-value from that which it actually has. Grossetesteholds that this kind of contingency of propositions about futureevents or things implies that the things or events the proposition isabout may themselves be called contingent, and that this kind ofcontingency is sufficient for the freedom of our future acts.

Much of Grosseteste’s discussion of modality revolves aroundchallenges posed by the concept of the eternal power of a propositionto be true or false without a beginning. He appears to hold suchpowers to be possessed not in time but in eternity. Grossetesteobserves that God also possesses eternal powers—namely, theability to know and will without a beginning. The difficultiesassociated with the eternal powers of propositions parallel those ofGod’s eternal powers. In fact, Grosseteste explains the eternalpowers of propositions in terms of God’s eternal powers to knowand will propositions and grounds non-temporal modality in God’spowers or lack thereof, particularly in the cases of necessity andimpossibility. For instance, he explains that

the eternal capacity for [thedictum] “that Antichristwas going to exist” to have had truth and not to have had truthwithout a beginning is nothing but the capacity of God by which Godwas able from eternity and without a beginning to will or not to willthat Antichrist will exist, or to know or not to know that Antichristwill exist. (Lewis 2017: 55)

The difficulties associated with the notion of eternal powers arisefrom the idea of unexercised yet genuine eternal powers, which seemsto be a requirement in Grosseteste’s account of non-temporalcontingency. When expressed in terms of God’s powers to know orwill, a challenge emerges regarding the meaning behind statements thatGodcould have not known or willed what he presently knows orwills, as implied by the doctrine that God possesses the power to notknow or not will what he knows or wills. According to Grosseteste, thephrase “could have” implies a priority of power to act,signifying that before God’s willing ofp, he had thepower not to will thatp. However, given that God existsoutside of time, “could have” cannot express a temporalpriority of God’s power over its act. Grosseteste addresses thisissue by proposing that it denotes acausal priority, aconcept he drew from Eriugena (see Lewis 1996).

The notion of unexercised eternal powers encounters the challenge thatthese powers, if genuine, seem to pertain to future acts and could beexercised in the future. For a timeless being like God, how could heexercise, at a future time, his power to know or will something hepresently does not know or will? Indeed, these powers are described aspowers to know or willwithout beginning. This attribution ofpower to God appears to be empty (frustra). Grossetestegrapples with a fundamental problem for those who, like him, positthat God is timeless yet possesses powers for actions he does notperform. His solution appeals to the idea that God’s powers toknow or will are rational powers, capable of multiple expressions(drawing from Aristotle’s concept of rational power). Therefore,the power to know thatp is identical to the power tonot-know thatp. With this understanding, if God knows thatp, his power to not-know thatp isipsofacto exercised, as it corresponds to the same power to know thatp. Consequently, there are no unexercised powers in God.Thomas Bradwardine critiqued this account, asserting that a moreplausible criterion for exercisability is that if an agent has thepower to know thatp and does not know thatp, thenhe can exercise that power by knowing thatp. Grossetestedoes not provide a response to this objection. A possible answer wouldrequire a more thorough examination of the relationship between power,time, and change than Grosseteste undertakes (see Lewis 1996).

9. Free Decision and Freedom of the Will

Accounts of human action and the associated freedom in the earlythirteenth century center around the concept of “freedecision” (liberum arbitrium). The expression“free decision” was understood to encompass not only aspecific type of act, as implied by its grammatical structure as aconcrete term, but also the capacity or capacities engaged in theexercise of such an act. The term “decision” typicallyimplicated reason, while “free” alluded to the will.Accordingly, inquiries often arose regarding whether “freedecision” pertains to an act of reason or will, and whether thecapacities involved in such an act are reason, will, a combination ofboth, or conceivably other capacities. Hence, medieval accounts offree decision offer valuable insights into the authors’understanding of human action and freedom.

According to Grosseteste’sOn Free Decision,“free decision” in its concrete usage refers to adecision, a specific type of rational act (on Grosseteste’stheory see Lewis 2013, 2017, and Pickavé 2017.) This act, likeany other act of reason, is not itself free but is described as freein a derivative sense because it guides the will, whose acts areconsidered free. Reason’s role is to differentiate between goodand bad, better and worse, and to suggest to the will what it shouldchoose or reject. The will, by its nature, makes choices or rejectionsbased on such guidance from reason but possesses the freedom todisregard reason’s decision and opt for an alternative choice.This freedom is the reason the decision is termed, in a derivativesense, afree decision. In presenting this view, Grossetesteimplies that he takes the will’s choices as not beingpsychologically determined by reason: indeed, reason offers advice,not necessity.

Grosseteste posits reason and will as the underlying capacities forfree decision, identifying them withaspectus andaffectus respectively. Influenced, perhaps, by thePseudo-AugustinianDe spiritu et anima’s discussion ofthe soul’s simplicity, Grosseteste maintains that thesecapacities are fundamentally one. However, this unified capacity canbe exercised through a decision in one way and through a choice inanother.

Grosseteste maintains that the freedom of decision is essentially thefreedom of the will. The nature of this freedom revolves around thewill’s capacity to choose alternatives, a concept referred to asflexibilitas orvertibilitas. This viewdistinguishes Grosseteste from many of his contemporaries who rejectthe idea that freedom of the will entails the capacity to willalternatives. Many of his contemporaries understand the pertinentalternatives to be moral good and evil, and emphasize that some agentswith freedom of the will (God and the angels) simply cannot will moralevil, whereas others (Satan and his cohorts) cannot will moral good.Hence, for them the freedom of the will cannot be defined as acapacity to turn between alternatives. Grosseteste challenges thisassumption by claiming that the alternatives in question are notnecessarily moral good and evil. He proposes that the freedom of thewill involves the capacity to turn between what he calls “bareopposites considered in themselves”. Although he providesminimal details about the notion of “bare opposites”, italigns with his belief, expressed inOn Free Decision, thatthe moral goodness or evil of an act depends on its relation toGod’s will, and acts are morally indifferent when consideredindependently of this relationship.

In Grosseteste’s framework, the freedom of the will is thewill’s capacity to choose alternatives in the sense of morallyindifferent alternatives. This does not imply that the chosen objectsare considered neither good nor bad. Grosseteste believes thatindividuals can only choose what they perceive to be good. However,the goodness involved in choosing these bare opposites is distinctfrom moral goodness: it isnatural goodness. Grossetesteprovides limited details about this notion. Yet, given his stance onthe non-determination of the will by reason, he likely believes thatan agent, when choosing among natural goods, can go againstreason’s guidance regarding the best or preferred option orabstain from making a choice aligned with reason’s dictate.

Grosseteste posits that our capacity for moral choice relies on theability to choose morally indifferent alternatives. However, heprovides little elaboration on this fundamental aspect. According tohim, humans cannot choose moral good without divine assistance,although he does not clarify the mechanisms by which divine grace,combined with the freedom of will, enables moral choice. Perhaps,Grosseteste envisions God’s grace making it possible forsomething willed by God, and therefore morally good, to serve as areason for human choice. Nevertheless, he emphasizes that the capacityto choose moral good is not inherent in possessing reason and willsince, otherwise, divine grace would be unnecessary. Similarly, thecapacity to choose moral evil stems from something extrinsic to reasonand will since God, who possesses both, cannot choose moral evil.Following Augustine, Grosseteste attributes the human capacity formoral evil to its creation ex nihilo, an inherent and inevitable flawin any created being. In individuals confirmed in good, this capacityremains unexercised by divine grace. As a result, they are incapableof making evil moral choices.

Accounts of free will are commonly distinguished between theoriesemphasizing the ability to do otherwise and theories centered onself-determination (see the entry, Free will). Grosseteste’stheory seems to better align with the former category. This alignmentis supported by his arguments for the existence of free decision,which point to a wide range of phenomena suggesting that an agentcould have chosen differently. However, there are hints of a moreprofound self-determination aspect in Grosseteste’s account. Hemaintains that the will’s capacity for opposites is inherentlycontained in its power to will and move itself (Lewis 2017: 255),portraying the will as a self-mover. Unfortunately, Grosseteste leavesthis aspect largely unexplored.

10. Exemplarism, Truth, and Illumination

10.1 Exemplarism

Grosseteste’s exemplarism (see Lynch 1941), represents anadaptation of Plato’s theory of Ideas within a Christianframework. In line with medieval thinkers, Grosseteste grapples withthe perceived inconsistency between the existence of an eternal,self-subsistent realm of Platonic Ideas and the dependence of allthings on God. Despite this tension, he interprets the Platonic Ideasas eternal models (exempla) and reasons (rationes)of things in God’s mind. These reasons serve as paradigms ormodels that created things can either align with or deviate from.Therefore, the act of creation is akin to a craftsman relying on theidea in her mind while crafting.

Given the absolute simplicity of God, Grosseteste ultimately equatesthe reasons of things in God’s mind with God himself.Grosseteste moves between speaking of the reasons in God’s mindas exemplars and of God himself as such. In alignment with Augustine,Grosseteste describes God as the first form, explicitly clarifyingthat he employs the term “form” differently fromAristotelian hylomorphism (Luard 1861: 4; Mantello & Goering 2010:38). InOn the Halt of Causes, he identifies God with“the form that is both a model and that in virtue of which athing is” and notes that this form “is not conjoined witha thing but exists on its own, simple and separate” (Baur 1912:125).

10.2 Truth

Grosseteste, writing in a tradition that explored the concept of truthacross various contexts. In his treatiseOn Truth, he delvesinto whether there is just one truth (veritas), which is God,or many truths (veritates). While discussing this,Grosseteste emphasizes a cohesive understanding of truth thatencompasses propositions, entities (such as trees or humans), and theidentification of God with truth. The doctrine of eternal exemplarforms plays an important role in this account.

According to Grosseteste, truth is the conformity or adequation ofthings and speech, specifically the thought expressed by speech. Thisconception was relatively new in the Latin West. Grossetesteinterprets it in a peculiar way, identifying the speech in questionwith that of God, the eternal Word. In this framework, truth(veritas) represents the conformity between things and theeternal Word. Grosseteste posits that the eternal Word is its ownconformity to itself, thus equating it with truth.

For created things, their truth is their conformity to their eternalmodel or reason in the eternal Word. Likewise, the truth ofpropositions—a subclass of things—is their conformity totheir eternal model or reason in the eternal Word. This, on firstappearance, would appear to clash with the idea that aproposition’s truth is not its conformity to anything in God,but rather to the state of affairs in the world whose obtaining itasserts. This appearance, however, is deceptive. A thing’sconformity to its eternal reason (its truth) is its possession of thebeing its exemplar specifies. Grosseteste holds that created itemshave two kinds of being or perfection. In his commentary on thePosterior Analytics, he holds that the second perfection of athing is

the completion of the activity of the thing to which it has, as such,been established to be fitted and for the sake of which it has beenestablished. (Rossi 1981: 240)

The first perfection of a thing is its simply being the kind of thingit is.

Consequently, there is a twofold conformity possible of things totheir eternal reasons. On the one hand, the eternal reason of a thingspecifies the very kind of thing that thing is, and simply in virtueof existing as an item of a determinate kind a thing will necessarilyconform to its exemplar in this respect and be true. Hence, all humanbeings and all propositions are true, in this sense, in that they arethe kinds of things they are, this being specified by their exemplar.A human being is a composite of body and soul, and a proposition is“the statement of one thing about another or one thing fromanother” (Baur 1912: 143). On the other hand, the eternal reasonspecifies the second perfection a thing ought to have but maynonetheless lack. In this sense a human being will be a false humanbeing if, for example, she is vicious, falling short of the perfectionof virtue specified in the eternal reason of a human being. Likewise,a proposition will be a false proposition if it fails to perform thefunction of a proposition, this being to state things as they in factare in the world. Thus, the ordinary notion of propositional truth,described by Aristotle as “to so be in the thing signified asspeech says”, is a matter of a proposition’s conformity,in respect of second being, to its eternal reason, and this is for itto perform the function perfective of propositions, namely, to be inconformity to the states of affairs it asserts.

Grosseteste’s account of truth aims to accommodate divergentconceptions prevalent in his day. Addressing whether there is onetruth or many, Grosseteste differs from Anselm and asserts theexistence of many truths (see Noone 2010). Despite this multiplicity,he contends that “there is a single truth that the name‘truth’ everywhere signifies and predicates” (Baur1912: 139). Hence, for Grosseteste any use of the term“truth” involves in some way a reference to the supremetruth, God.

10.3 Illumination

Influenced by Augustine, Grosseteste adopts an illuminationistperspective on human knowledge. According to this account, humanknowledge is understood by analogy to bodily vision: as a body canonly be seen if light is shed on it and the eyes, so something canonly be known if a spiritual light is shed on it and the mind’seye. Grosseteste articulates variations of this account in his works,particularly inOn Truth and hisPosterior Analyticscommentary.

InOn Truth, Grosseteste presents an illuminationist theoryof knowledge closely following his theory of truth. Because createdtruth is a conformity between things and their eternal reasons, we canonly know created truth if we know that a created thing conforms toits eternal reason in God. Drawing an analogy with a colored body,which is seen only when external light makes it visible, Grossetesteargues that to see a created thing as true, an externallight—emanating from the Supreme Truth, God—mustilluminate its truth, making it visible. This truth is the adequationof the thing and its eternal reason in God’s mind, which makesclear why the light of God needs to be shed on both the thing and itseternal reason if it is to be visible to the human mind. Grossetesteemphasizes that this process does not necessitate direct awareness orvision of God, as the pure of heart alone possess such a vision.Nevertheless, all who know truth must, in some way, have at least anunwitting cognition of the Supreme Truth and its light, and, in it, avision of the eternal reasons.

On Truth does not explicitly refer to Aristotle’s viewson knowledge but instead draws on the ideas of Augustine and Anselm.However, in his likely earlierPosterior Analyticscommentary, Grosseteste connects an illuminationist conception ofknowledge to Aristotle’s explanation of scientific knowledge.Nevertheless, scholars disagree concerning Grosseteste’sintentions in this regard. Some scholars (Gilson 1926–7; Lynch1941; McEvoy 1982) argue that Grosseteste does not incorporateAristotle’s notion of abstraction, instead favoring anAugustinian conception of divine illumination. Others (Marrone 1983),takingOn Truth as an earlier work, suggest thatGrosseteste’s commentary rejects his previous claims on divineillumination for human knowledge and associates Grosseteste’sreferences to illumination with an Aristotelian process of abstractionas the light that the human soul itself sheds on intelligible things.However, as Van Dyke (2009) argues, Grosseteste seems to aim atintegrating Aristotle’s account of scientific knowledge into abroader cognitive framework where divine illumination plays asignificant role in all cognition. At the same time, Grossetesteendorses the account of scientific knowledge and abstraction found inthePosterior Analytics. (For a more in-depth discussion andtechnical aspects of Grosseteste’s account of demonstrativescience, see the entry on Medieval Theories of Demonstration, as wellas Crombie 1953; Evans 1983; W. R. Laird 1987; Longeway 2007; McEvoy1982; Marrone 1983 & 1986; Rossi 1995; Serene 1979; Van Dyke 2009& 2010; and Wallace 1972.)

ThePosterior Analytics provides an account of scientificknowledge (scientia). In this context, scientific knowledgerefers not to modern scientific theories based on experimentaltesting. Instead, it corresponds to an understanding of why a givenfact obtains (knowledgepropter quid), as opposed toknowledge simply that the fact does obtain (knowledgequia).Aristotelian science involves systematizing such knowledge adoptingthe structure of Euclid’s axiomatic geometry andAristotle’s syllogistic logic.

Scientia is attained by deriving a fact as the conclusion ofa syllogism with premises meeting strict conditions: they must betrue, immediate, prior, better known than the conclusion, statecauses, be necessary, involve essential connections, be universal,everlasting, and incorruptible. Such a syllogism is termed ademonstrative syllogism or demonstration, and it provides explanatoryknowledge of its conclusion. Grosseteste even suggests that onlymathematics strictly comprises demonstrations, but he also hints thattheology might fulfill these criteria more fully, distinguishing thedemonstrative knowledge we can achieve in this life (mathematics) fromthat which is possible in the afterlife (theology). The sciences ofnatural phenomena, Grosseteste contends, fall short of fully meetingthese criteria. Yet, if we soften the criteria mentioned above, ademonstrative science for natural phenomena is indeed possible (seethe entry on Medieval Theories of Demonstration for details).

In Grosseteste’s view, thePosterior Analytics does notaim to provide a method for arriving at demonstrations, but rather toestablish criteria for determining whether a given syllogism qualifiesas a demonstration. While Aristotle discusses the origin of theprinciples and definitions employed in demonstrations, it is inexamining these aspects that Grosseteste introduces the concepts ofmental vision and the illumination of the mind.

According to Aristotle, universal concepts and principles of a scienceare derived from sense experience. Consequently, if an individuallacks a particular sense, their scientific knowledge of the conceptsrelated to the exercise of that sense will also be lacking. However,Grosseteste holds that God and intelligences (i.e., the angels)possess knowledge independent of sensory experiences. Similarly, thehighest part of the human soul, the intellective power, does not relyon bodily senses in its proper operation. Instead, the latter involvesa mental vision, acquiring knowledge of things by seeing the exemplarforms or reasons through an irradiation received from God or anintelligence.

Grosseteste harmonizes this perspective with Aristotle’spositions by holding that, with rare exceptions, most individuals intheir present life lack this form of knowledge. Their intellectivepower is “sick”, unable to perform its proper operation.In present life, Aristotelian demonstrative science represents thehighest form of knowledge accessible to most individuals, and itrequires sensory experience.

The human intellective power is sick due to the darkening and burdenimposed by the corrupt body—likely a consequence of the Fall.The operation of the cognitive powers is darkened by bodilyappearances (phantasmata), which obscure mental vision andprevent the clear perception of intelligible entities. This darkeningof the mind is the origin of all errors. However, in the process ofgrasping the principles of demonstration, reason is prompted toovercome this darkness. Sensory experience, in some way, engagesreason. From birth, repeated sensory experiences stimulate reason,allowing it to distinguish and discern the features initially blurredin sensory experiences and formulate universal concepts. The repeatedexperience of correlated perceptible phenomena leads the senses toinfer imperceptible relationships among them. This awakening of reasonleads to a questioning of whether these inferred connections areindeed accurate. Grosseteste illustrates this with an example borrowedfrom Avicenna, discussing the assertion that scammony, by itself,causes the discharge of red bile. Questioning the validity of thisclaim, we set up what we may call a “controlledexperiment” by eliminating other known causes of red biledischarge and administering scammony to observe the outcomes.Grosseteste maintains that this process allows us to arrive“from sense at an observational (experimentale)universal principle” (Rossi 1981: 215). Hence, the mind movesout of the darkness to find a trace of its light. As Grosseteste putsit in discussing certainty,

there is a spiritual light shed on intelligible things and themind’s eye, and this light is related to the inner eye andintelligible things in the way the bodily sun is related to bodilyeyes and visible bodily things. (Rossi 1981: 240–241)

These remarks suggest that Grosseteste sees a role for spiritual lightand vision in scientific knowledge. However, they also indicate hisadherence to an Aristotelian framework where the human mind abstractsintelligible elements from sensory data. These intelligible items seemto align with the genera and species of created things, viewed asimmanent universals.

The kind of vision and illumination that Grosseteste discusses inrelation to scientific knowledge, and particularly in his account ofdemonstrative science, is still unclear. Is he employing a notion ofdivine illumination in this context, too, as he does inOn Truth? Marrone (1983) suggests that he is not: the lighthe mentions is one that the mind itself generates to make objectsintelligible and this theory does not impact Grosseteste’saccount of Aristotelian science. Accordingly, thePosteriorAnalytics commentary would display a turn away from theconception of knowledge inOn Truth in terms of divineillumination towards a purely naturalistic conception of knowledge.This interpretation, however, leans on the assumption thatOnTruth was written before the commentary. Moreover, as van Dyke(2009) emphasizes, this view seems inconsistent withGrosseteste’s analogy between the light in scientific knowledgeand in bodily vision, suggesting that the light in scientificknowledge is external, emanating from a source beyond the mind, suchas God or an intelligence, to render objects intelligible.

11. Scientific Method

Grosseteste’s keen interest in natural philosophy and sciencestands as a defining aspect of his intellectual pursuits. He authorednumerous short scientific treatises, delving into specific issues andproblems directly related to the natural world. This interest in thenatural realm also permeates, in various ways, his philosophical andtheological works. Over the past century, scholars have argued thatGrosseteste played a pivotal role in shaping the scientific method. Inparticular, Crombie (1955, summarizing his work from 1953),claimed

1. that Grosseteste was the first in the Latin West to articulate anexperimental method in science (1955: 98);
2. that he “seems to have been the first writer to makesystematic use of a method of experimental verification andfalsification” (1955: 107);
3. that he attributed “special importance to mathematics inattempting to provide scientific explanations of the physicalworld” (1955: 111).

These claims, however, have sparked considerable debate.

At first sight, the claim that Grosseteste developed an account ofexperimental method in science may be inferred from the passagesdescribing a controlled experiment to test the effects of scammony onthe discharge of red bile mentioned above (§10.3) While it is evident that Grosseteste contemplates the idea of acontrolled experiment, the question arises as to whether he integratesthis notion into a broader framework for scientific method inacquiring the principles of demonstrative science. The evidencesupporting this claim is not robust. The discussion of scammonyremains the sole reference to controlled experiments in his writings.When Grosseteste revisits this discussion later in the commentary toexplain how we come to acquire experiential principles, theapplicability of the notion of controlled experiment becomesquestionable, for example, in the case of our understanding of thecause of an eclipse. Additionally, Grosseteste acknowledges that, incertain instances, knowledge of causal connections can be gained aftera single perception (see Marrone 1986). In summary, while Grossetestedid utilize the concept of controlled experiments and connected it todemonstrative science, he did not elevate it to the status ofthe method for acquiring such knowledge. Controlledexperiments are viewed as one among various approaches.

Concerning Grosseteste’s actual practice in his scientificwritings, if an experimental method is understood as a controlledexperiment, then it must be noted that Grosseteste does not employ it.His conclusions are usually drawn from a combination of factors. Herelies on authority and everyday observation (experimentum),engages in thought experiments, and incorporates certain metaphysicalassumptions, such as the principle that “every operation ofnature occurs in the most finite, ordered, shortest and best waypossible for it” (Baur 1912: 75). Nowhere does Grossetesteexplicitly outline a controlled experiment as the foundation for hisconclusions (see Eastwood 1968, regarding Grosseteste’s works inoptics). It can be acknowledged that Grosseteste refers to empiricalobservation as one element among many when assessing the adequacy ofcertain accounts of natural phenomena. However, this is far fromemploying a method of experimental verification and falsification inthe specific sense of a controlled experiment.

The assertion that Grosseteste assigned “special importance tomathematics in attempting to provide scientific explanations of thephysical world” stands on firmer ground. In the opening ofOn Lines, Angles and Figures, Grosseteste underscores thesignificance of geometry for our understanding of natural philosophy(see Baur 1912: 59–60). Moreover,On the Nature ofPlaces (a continuation ofOn Lines, Angles and Figures)concludes by stating that the natural philosopher can explain naturalcausation by the “power of geometry” (Baur 1912: 65).Therefore, it is evident that Grosseteste attributed a crucial role togeometry in explaining natural phenomena.

This perspective was grounded in Grosseteste’s belief thatnatural agents exert their influence through the multiplication oftheir power or species, a concept that Roger Bacon later developed indetail. Grosseteste was, of course, thinking of the action of light.He argues that knowledgepropter quid must be through angles,lines, and figures because a “natural agent multiplies its powerfrom itself to what it acts upon, whether it act upon the senses orupon matter” (Baur 1912: 60). Grosseteste maintains that theintensity of a natural agent’s operation depends on factors suchas its distance from the target, the angle of impact, and the figurethrough which it multiplies its operation (either a sphere or a cone).He establishes rudimentary rules, including the notion that a shorterdistance results in a stronger operation.

These aspects highlight Grosseteste’s profound interest in thethorough examination of natural phenomena. His mindset, together withhis emphasis on the significance of mathematics, may be considered hisprimary contribution to the development of an incipient mathematicalphysics in fourteenth-century Oxford.

12. Influence

Grosseteste’s influence extended to numerous thinkers,particularly those active in Oxford. Their number includes Adam ofWodeham, John Wyclif, Robert Kilwardby, Thomas Bradwardine, ThomasBuckingham, Thomas of York, Walter Burley, William of Alnwick, Williamof Ockham, and others. Leaving aside his commentary on thePosterior Analytics, Grosseteste’s greatest impact as aphilosopher was as a source of new ideas for thinkers flourishing inthe first half of the thirteenth century. Richard Rufus of Cornwallmakes extensive use of Grosseteste’s writings in his largeScriptum on Aristotle’sMetaphysics and hisOxford commentary on theSentences of Peter Lombard, as doeshis Oxford contemporary Richard Fishacre in his commentary on theSentences. These thinkers drew inspiration fromGrosseteste’sOn Free Decision and his writings on theeternity of the world. Rufus also praises Grosseteste’sscientific and mathematical expertise, as does Roger Bacon, a man bytemperament more given to scorn than praise.

In the fourteenth century, Grosseteste held an uncommon position as anauthoritative figure for Oxford philosophers. Thinkers such as ThomasBradwardine and Thomas Buckingham appealed to Grosseteste in supportof their conflicting views on future contingency. John Wyclif likewiseinvoked Grosseteste’s writings to bolster his views on thecontinuum, among other issues. These examples illustrate the highregard and reverence in which Grosseteste was held in Oxford duringthis period.

In the Continent, Grosseteste’s philosophical impact primarilycentered around his expertise as a scholar of Aristotle. HisPosterior Analytics commentary gained recognition and waswidely used throughout the Middle Ages, showcasing his influence inmedieval thought (for its influence in Britain, see Rossi 2012.)Grosseteste’s translation of Aristotle’sEthicsalso had a meaningful impact. Beside these two crucial works, it isnoteworthy that the fourteenth-century French thinker Nicole Oresmemakes use of various philosophical and scientific treatises authoredby Grosseteste, most notably in hisQuestionessuperPhysicam.

Bibliography

A. Bibliographies

• Gieben, Servus, 1962, “Bibliographia universa RobertiGrosseteste ab anno 1473 ad annum 1960”,CollectaneaFranciscana, 39: 362–418.
• –––, 1995, “Robertus Grosseteste:Bibliographia 1970–1991”, inMcEvoy 1995: 415–431.
• Thomson, S. Harrison, 1940,The Writings of RobertGrosseteste, Bishop of Lincoln, 1235–1253, Cambridge:Cambridge University Press.

B. Biographical Studies

Important biographical material may also be found in a number of themore general studies listed below, especiallySouthern 1986,McEvoy 1982, andMcEvoy 2000. Grosseteste’s early career remains a matter of controversy. Theliterature is filled with unjustified assertions of fact and outrighterrors regarding this part of his life and readers must be on theirguard.

• Callus, Daniel A., 1945, “The Oxford Career of RobertGrosseteste”,Oxoniensia, 10: 42–72. [Callus 1945 available online]
• Ginther, James R., 2000, “Natural Philosophy and Theology atOxford in the Early Thirteenth Century”,Medieval SermonStudies, 44: 108–134.
• Goering, Joseph, 1995, “Where and When did Grosseteste StudyTheology”, inMcEvoy 1995: 17–51.

• Schulman, N. M., 1997, “Husband, Father, Bishop? Grosseteste inParis”,Speculum, 72(2): 330–346.doi:10.2307/3040973

  [This article argues on the basis of documentary sources thatGrosseteste lived in Paris as a married (and ultimately widowed)father prior to teaching at Oxford and his episcopacy. This view iscriticized byMcEvoy 2003: 19–20, who notes Grosseteste’s remark in one of hisprayers that he had never polluted his body with the stain of theflesh.]

C. Primary Texts in Latin

It is important to note that some of the texts quoted above fromBaur 1912 andDales 1963a rely on tacit alterations that Neil Lewis has made to the Latin texton the basis of his consultation of the manuscripts. The editions havebeen arranged chronologically and categorized based on the types ofwritings authored by Grosseteste (see section 2).

C.1 Scientific treatises

• Baur, Ludwig (ed.), 1912,Die Philosophischen Werke des RobertGrosseteste, Bischofs von Lincoln (Beiträge zur geschichteder philosophie des mittelalters 9), Münster: AschendorffVerlag.

  [This text includes the standard edition of Grosseteste’sscientific treatises. However, this edition is unreliable and a numberof works in it have been reedited (see below.)]

• Panti, Cecilia (ed.), 2001,Moti, virtù e motori celestinella cosmologia di Roberto Grossatesta: studio ed edizione deitrattati De sphera, De cometis, De motu supercelestium (Testi estudi per il “Corpus philosophorum Medii Aevi” 16),Firenze: SISMEL: Edizioni del Galluzzo.

  [Critical editions ofDe sphaera, De cometis, De motusupercaelestium that supersede the editions of these works inBaur. The same text critically edited by Panti is presented in Gasper,McLeish, Smithson, and Sønnesyn 2023: 96–130.]

• Dinkova-Bruun, Greti, Tom McLeish, Giles E. M. Gasper, M.Huxtable, Cecilia Panti, and Hannah Smithson (eds/trans), 2013,The Dimensions of Colour: Robert Grosseteste’s “Decolore” (Durham Medieval and Renaissance Texts 4), Durham,UK/Toronto: Institute of Mediaeval and Renaissance Studies, DurhamUniversity/Pontifical Institute of Mediaeval Studies.
• Gasper, Giles E. M., Cecilia Panti, Tom McLeish,and Hannah E. Smithson (eds.), 2019,The Scientific Works of RobertGrosseteste. Vol. 1: Knowing and Speaking, Oxford: OxfordUniversity Press. doi:10.1093/actrade/9780198805519.book.1
• Gasper, Giles E. M., Tom C. B. McLeish, Hannah E. Smithson, andSigbjørn Olsen Sønnesyn (eds.), 2023,The ScientificWorks of Grosseteste (Volume II:Mapping the Universe),Oxford: Oxford University Press.
• Sønnesyn, Sigbjørn O. (ed.), 2019, “Deartibus liberalibus” (On the Liberal Arts), inGasper, Panti, McLeish, and Smithson 2019: 74–94.
• ––– (ed.), 2019, “De generationesonorum” (On the Generation of Sounds), inGasper, Panti, McLeish, and Smithson 2019: 244–254.

C.2 Philosophical treatises

• Baur, Ludwig (ed.), 1912,Die Philosophischen Werke des RobertGrosseteste, Bischofs von Lincoln (Beiträge zur geschichteder philosophie des mittelalters 9), Münster: AschendorffVerlag.

  [This text includes the standard edition of Grosseteste’sphilosophical treatises, too. As noted above, Baur’s edition isunreliable and new editions of Grosseteste’s works supersede it(see below.)]

• Dales, Richard C. (ed.), 1963b, “Robert Grosseteste’sTreatise ‘De finitate motus et temporis’”,Traditio, 19: 245–266.doi:10.1017/S0362152900010400

  [This edition supersedes the edition inBaur 1912.]

• Lewry, P. Osmund (ed.), 1983, “Robert Grosseteste’sQuestion on Subsistence: An Echo of the Adamites”,MediaevalStudies, 45: 1–21. doi:10.1484/J.MS.2.306298

  [The article contains an edition ofDe subsistentia rei.]

• Panti, Cecilia (ed.), 2011,Roberto Grossatesta, La luce,Pisa: PLUS-Pisa University Press.

  [Text of the critical edition inPanti 2013a, but without the critical apparatus. The Latin text is accompanied byan Italian translation and commentary.]

• –––, 2013a, “Robert Grosseteste’sDeluce: A Critical Edition”, inFlood, Ginther, and Goering 2013: 193–238.

  [A critical edition ofDe luce that supersedes the edition inBaur 1912.]

C.3 Commentaries on Aristotle

• Dales, Richard C. (ed.), 1963a,Roberti Grosseteste episcopiLincolniensis commentarius in viii libros Physicorum Aristotelis,Boulder, CO: University of Colorado Press.

  [Unfortunately, a flawed edition of this important work that must beused with great caution. A new edition is in preparation by N. Lewisand P. King.]

• Rossi, Pietro (ed.), 1981,Commentarius in PosteriorumAnalyticorum Libros, Florence: Leo S. Olschki.

C.4 Philosophical-theological works

• Luard, Henry Richards (ed.), 1861,Roberti Grosseteste Episcopiquondam Lincolniensis Epistolæ (Rerum Britannicarum MediiÆvi Scriptores 25), London: Longman, Green, Longman, andRoberts.

  [Luard’s edition of Grosseteste’s first letter, thougholder, is better than that found inBaur 1912, where Baur prints it, following many manuscripts, as the two worksDe unica forma omnium andDe intelligentiis.]

• McEvoy, James (ed.), 1974, “The Sun asres andsignum: Grosseteste’s commentary onEcclesiasticus, ch. 43, vv. 1–5”,Recherchesde théologie ancienne et médiévale, 41:38–91; reprinted inMcEvoy 1994.

  [This commentary is also known asDe operationibussolis.]

• Lewis, Neil Timothy (ed.), 2017,Robert Grossteste “On FreeDecision” (Auctores Britannici Medii Aevi 29), Oxford/NewYork: Published for the British Academy by Oxford UniversityPress.

  [Editions and English translation of the two recensions ofGrosseteste’sDe libero arbitrio. It supersede theeditions inBaur 1912.]

C.5 Theological Works

• McEvoy, James (ed.), 1980, “Robert Grosseteste’sTheory of Human Nature With the Text of His Conference ‘EcclesiaSancta Celebrat’”,Recherches de théologieancienne et médiévale, 47: 131–187. ReprintedinMcEvoy 1994.
• Dales, Richard C. and Servus Gieben (eds.), 1982,RobertGrosseteste: Hexaëmeron (Auctores Britannici Medii Aevi 6),London/New York: Published for the British Academy by the OxfordUniversity.
• Dales, Richard C. and Edward B. King (eds.), 1986,RobertGrosseteste: De cessatione legalium (Auctores Britannici MediiAevi 7), London/New York: published for the British Academy by theOxford University Press.
• ––– (eds.), 1987,Robert Grossetese: De DecemMandatis (Auctores Britannici Medii Aevi 10), Oxford: publishedfor the British Academy by Oxford University Press.

C.6 Other writings

• Rosemann, Philipp W. (ed.), 1995, “Tabula”, inOpera Roberti Grosseteste Lincolniensis 1 (CorpusChristianorum 130), Turnhout: Brepols.

D. Primary Texts in English Translation

D.1 Scientific treatises

• Crombie, A. C., 1955, “Grosseteste’s Position in theHistory of Science”, inRobert Grosseteste: Scholar andBishop, Daniel A. Callus (ed.), Oxford: Clarendon Press,98–120.

  [Contains a translation ofDe calore solis (116–120).The authenticity of this work is challenged inPanti 2013b.]

• Dales, Richard C., 1966, “The Text of Robert Grosseteste’sQuestio de fluxu et refluxu maris with an EnglishTranslation”,Isis, 57(4): 455–474. Reprinted inA Source Book in Medieval Science, Edward Grant (ed.),Cambridge, MA: Harvard University Press, 640–644; and inDales 1973. doi:10.1086/350162

  [The authenticity of this work is challenged inDales 1977,Southern 1986, andPanti 2013b.]

• –––, 1973,The Scientific Achievement of theMiddle Ages, Philadelphia, PA: University of PennsylvaniaPress.

  [Contains translations ofDe impressionibus elementorum,De calore solis andDe fluxu et refluxu maris. Theauthenticity of the last work is challenged inDales 1977,Southern 1986, andPanti 2013b. Panti 2013b also challenges the authenticity ofDe caloresolis]

• Lindberg, David C. (trans.), 1974, “Robert Grosseteste and theRevival of Optics in the West”, inA Source Book in MedievalScience, Edward Grant (ed.), Cambridge, MA: Harvard UniversityPress, 384–391.

  [Translations ofDe lineis, angulis et figuris (ConcerningLines, Angles, and Figures) andDe iride (On theRainbow).]

• Sønnesyn, Sigbjørn Olsen, 2019a, “On theLiberal Arts”, inGasper, Panti, McLeish, and Smithson 2019: 75–95.
• –––, 2019b, “On the Generation ofSound”, inGasper, Panti, McLeish, and Smithson 2019: 245–255.

• –––, 2023, “Onthe Sphere”, in Gasper, McLeish, Smithson, and Sønnesyn2023, 97–131. doi:10.1093/actrade/9780198805526.book.1

  [Translation based on the critical edition inPanti 2001.]

D.2 Philosophical treatises

• McKeon, Richard (trans.), 1929,Selections from MedievalPhilosophers, Volume 1. New York: Charles Scribner’s Sons,263–287.

  [Translations ofDe veritate,De veritatepropositionis, andDe scientia Dei based on the text inBaur 1912.]

• Lewis, Neil, 2013, “Robert Grosseteste’sOnLight: An English Translation”, inRobert Grossetesteand His Intellectual Milieu, John Flood, James R. Ginther, andJoseph W. Goering (eds.), Toronto: Pontifical Institute of MediaevalStudies, 239–247. doi:10.1515/9781771103534-015

  [A translation ofDe luce based on the critical edition inPanti 2013a.]

D.3 Theological-philosophical works

• Lewis, Neil Timothy (trans.), 2017,The Two Recensions of“On Free Decision” (Auctores Britannici Medii Aevi29), Oxford/New York: Published for the British Academy by OxfordUniversity Press.

  [Editions and English translation of the two recensions ofGrosseteste’sDe libero arbitrio.]

• Mantello, Frank Anthony Carl and Joseph Goering (trans), 2010,TheLetters of Robert Grosseteste, Bishop of Lincoln, Toronto:University of Toronto Press.

  [An annotated translation of Grosseteste’s letters, includingthe first letter, which circulated in the middle ages as two works,De unica forma omnium andDe intelligentiis.]

D.4 Theological works

• Martin, C. F. J. (trans.), 1996,Robert Grosseteste on the SixDays of Creation: A Translation of the Hexaëmeron (AuctoresBritannici Medii Aevi, 6 (2)), Oxford/New York: Published for theBritish Academy by Oxford University Press.

• Hildebrand, Stephen M. (trans.), 2012,On the Cessation of theLaws (The Fathers of the Church, Mediaeval Continuation 13),Washington, DC: Catholic University of America Press.

  [A translation ofDe cessatione legalium]

E. Secondary Literature

• Baur, Ludwig, 1917,Die Philosophie des Robert Grosseteste,bischofs von Lincoln (Beiträge zur Geschichte derPhilosophie des Mittelalters, bd. XVIII, hft. 4–6),Münster: Aschendorff Verlag.
• Beullens, Pieter, 2023a, “Robert Grosseteste’sTranslation of Simplicius’s Commentary on Aristotle’s DeCaelo: Tracking down a Second Manuscript and the Greek Model”,Mediterranea. International Journal on the Transfer ofKnowledge, 8: 565–594. doi:10.21071/mijtk.v8i.15273
• –––, 2023b, “Robert Grosseteste and theFluid History of the Latin ‘Nicomachean Ethics’”,Revista Española de Filosofía Medieval, 30(1):177–198. doi:10.21071/refime.v30i1.15609
• Callus, Daniel Angelo Philip, 1955, “Robert Grosseteste asScholar”, inRobert Grosseteste: Scholar and Bishop. Essaysin Commemoration of the Seventh Centenary of His Death, DanielAngelo Philip Callus (ed.), Oxford: Clarendon Press, 1–69.

• Crombie, A. C., 1953,Robert Grosseteste and the Origins ofExperimental Science, 1100–1700, Oxford: Clarendon Press.

  [An important but controversial book.]

• Cunningham, Jack P. (ed.), 2012,RobertGrosseteste: His Thought and Its Impact (Papers in MediaevalStudies 21), Toronto: Pontifical Institute of Mediaeval Studies.

• Cunningham, Jack P. and Mark Hocknull (eds.), 2016,RobertGrosseteste and the Pursuit of Religious and Scientific Learning inthe Middle Ages (Studies in the History of Philosophy of Mind18), Cham: Springer. doi:10.1007/978-3-319-33468-4

  [The volume offers many important contributions to the study of RobertGrosseteste’s thought.]

• Dales, Richard C., 1961, “Robert Grosseteste’sScientific Works”,Isis, 52(3): 381–402.doi:10.1086/349477
• –––, 1977, “Adam Marsh,Robert Grosseteste, and the Treatise on the Tides”,Speculum, 52(4): 900–901. doi:10.2307/2855379
• –––, 1986, “Robert Grosseteste’sPlace in Medieval Discussions of the Eternity of the World”,Speculum, 61(3): 544–563. doi:10.2307/2851595
• Devriese, Lisa, 2023, “The History of RobertGrosseteste’s Translations within the Context of‘Aristoteles Latinus’”,Revista Españolade Filosofía Medieval, 30(1): 199–222.doi:10.21071/refime.v30i1.16127
• Dionisotti, A. C., 1988, “On the Greek Studies of RobertGrosseteste”, inThe Uses of Greek and Latin: HistoricalEssays (Warburg Institute Surveys and Texts 16), A. C.Dionisotti, Anthony Grafton, and Jill Kraye (eds.), London: The WarburgInstitute, University of London, 19–39.
• Eastwood, Bruce S., 1968, “Mediaeval Empiricism: The Case ofGrosseteste’s Optics”,Speculum, 43(2):306–321. doi:10.2307/2855937
• Evans, Gillian Rosemary, 1983, “TheConclusiones ofRobert Grosseteste’s Commentary on thePosteriorAnalytics”,Studi Medievali, series 3, 24:729–734.

• Flood, John, James R. Ginther, and Joseph Goering (eds.), 2013,Robert Grosseteste and His Intellectual Milieu: New Editions andStudies (Papers in Mediaeval Studies 24), Toronto: PontificalInstitute of Mediaeval Studies.

  [This volume offers new editions and translations ofGrosseteste’s works as well as important studies.]

• Gauthier, R. A., 1982, “Notes sur les débuts(1225–1240) du premier ‘Averroïsme’”,Revue des Sciences philosophiques et théologiques,66(3): 321–374.
• Gieben, Servus, 2003, “Grosseteste and UniversalScience”, inRobert Grosseteste and the Beginnings of aBritish Theological Tradition: Papers Delivered at the GrossetesteColloquium Held at the Greyfriars, Oxford on 3rd July 2002(Bibliotheca Seraphico-Capuccina 69), Maura O’Carroll (ed.),Roma: Istituto storico dei Cappuccini, 219–238.
• Gilson, Étienne, 1926–7, “Pourquoi Saint Thomasa Critiqué Saint Augustin”,Archives d’histoiredoctrinale et littéraire du Moyen Âge, 1:5–127.
• Laird, W. R., 1987, “Robert Grosseteste on the SubalternateSciences”,Traditio, 43: 147–169.doi:10.1017/S0362152900012514
• Laird, Edgar, 2013, “Robert Grosseteste, Ptolemy, andChristian Knowledge”, inFlood, Ginther, and Goering 2013: 131–152. doi:10.1515/9781771103534-011
• Lewis, Neil, 1996, “Power and Contingency in RobertGrosseteste and Duns Scotus”, inJohn Duns Scotus:Metaphysics and Ethics (Studien und texte zur Geistesgeschichtedes Mittelalters 53), Ludger Honnefelder, Rega Wood, and MechthildDreyer (eds.), Leiden: Brill, 205–225.
• –––, 1998, “The Problem of a Plurality ofEternal Beings in Robert Grosseteste”,Medieval Philosophy& Theology, 7(1): 17–38.doi:10.5840/medievalpt1998712
• –––, 2003, “Robert Grosseteste’sNotes on the Physics”, inMackie and Goering 2003: 103–134 (ch. 5). doi:10.3138/9781442674271-008
• –––, 2005, “Robert Grosseteste and theContinuum”, inAlbertus Magnus and the beginnings of themedieval reception of Aristotle in the Latin West: from RichardusRufus to Franciscus de Mayronis (Subsidia Albertina 1), LudgerHonnefelder, Rega Wood, Mechthild Dreyer, and Marc-Aeilko Aris (eds.),Münster: Aschendorff Verlag, 159–187.
• –––, 2009, “Grosseteste on Being”,The Modern Schoolman, 86(1): 25–46.doi:10.5840/schoolman2008/2009861/22
• –––, 2012, “Robert Grosseteste and RichardRufus of Cornwall on Unequal Infinites”, inCunningham 2012: 227–256.
• –––, 2013, “Libertas arbitrii inRobert Grosseteste’sDe libero arbitrio”, inFlood, Ginther, and Goering 2013: 11–33. doi:10.1515/9781771103534-006
• –––, 2023, “Corporeity,Corpus-Substantia, andCorpus-Quantum inGrosseteste’s Commentaries on thePhysics andPosterior Analytics”,Revista Española deFilosofía Medieval, 30(1): 149–175.doi:10.21071/refime.v30i1.16366

• Longeway, John, 2007,Demonstration and Scientific Knowledge inWilliam of Ockham: A Translation of Summa logicae III-II: Desyllogismo demonstrativo, and Selections from the Prologue to theOrdinatio, Notre Dame, IN: University of Notre Dame Press.

  [See pp. 13–46 for an account of Grosseteste’s views ondemonstrative science.]

• Lynch, Lawrence E., 1941, “The Doctrine of Divine Ideas andIllumination in Robert Grosseteste, Bishop of Lincoln”,Mediaeval Studies, 3: 161–173.doi:10.1484/J.MS.2.305864
• Mackie, Evelyn A. and Joseph Goering (eds.), 2003,Editing Robert Grosseteste: Papers given at the Thirty-SixthAnnual Conference on Editorial Problems, University of Toronto,3–4 November 2000 (Previous Conference Publications 2000),Toronto: University of Toronto Press. doi:10.3138/9781442674271

• Marrone, Steven P., 1983,William of Auvergne and RobertGrosseteste: New Ideas of Truth in the Early Thirteenth Century,Princeton, NJ: Princeton University Press.

  [An important study of Grosseteste’s epistemology, thoughMarrone’s view that Grosseteste was distancing himself from anilluminationist epistemology in the commentary on thePosteriorAnalytics is generally rejected by scholars.]

• –––, 1986, “Robert Grosseteste on theCertitude of Induction”, inL’homme et son univers aumoyen âge: actes du septième Congrès internationalde philosophie médiévale (30 août – 4 septembre1982), Volume 2 (Philosophes médiévaux 27),Christian Wenin (ed.), Louvain-la-Neuve: Editions de l’Institutsupérieur de philosophie, 481–488.

• McEvoy, James J., 1982,The Philosophy of Robert Grosseteste, Oxford: ClarendonPress. Corrected reprint, 1986.

  [A magisterial study of Grosseteste’s thought. This workincludes significant material on Grosseteste’s theological viewsin his commentaries on the pseudo-Dionysius.]

• –––, 1983, “The Chronology of RobertGrosseteste’s Writings on Nature and Natural Philosophy”,Speculum, 58(3): 614–655.

• –––,1994,Robert Grosseteste, Exegete and Philosopher (VariorumCollected Studies Series CS446), Aldershot/Brookfield, VT:Variorum.

  [A collection of articles written by this pre-eminent student ofGrosseteste.]

• ––– (ed.), 1995,RobertGrosseteste: New Perspectives on His Thought and Scholarship(Instrumenta Patristica 27), Turnhout: Brepols Publishers.doi:10.1484/M.IPM-EB.5.112138

• –––,2000,Robert Grosseteste (Great Medieval Thinkers), New York:Oxford University Press.

  [An excellent overview of Grosseteste’s life and thought;essential first reading for the prospective student ofGrosseteste.]

• –––, 2003, “RobertGrosseteste: The Man and His Legacy”, inMackie and Goering 2003: 1–30 (ch. 1). doi:10.3138/9781442674271-004
• Noone, Timothy, 2010, “Truth, Creation, and Intelligibilityin Anselm, Grosseteste, and Bonaventure”, inTruth: Studiesof a Robust Presence (Studies in Philosophy and the History ofPhilosophy 51), Kurt Pritzl (ed.), Washington, DC: Catholic Universityof America Press, 102–126 (ch. 3).
• Oliver, Simon, 2004, “Robert Grosseteste on Light, Truth andExperimentum”,Vivarium, 42(2): 151–180.doi:10.1163/1568534043084739
• Palma, Robert J., 1975, “Robert Grosseteste’sUnderstanding of Truth”,Irish Theological Quarterly,42(4): 300–306. doi:10.1177/002114007504200406
• –––, 1976, “Grosseteste’s OrderingofScientia”,New Scholasticism, 50(4):447–463. doi:10.5840/newscholas19765043
• Panti, Cecilia, 1999, “L’incorporazione della lucesecondo Roberto Grossatesta”,Medioevo e rinascimento,new series, 13(10): 45–102.
• –––, 2003, “Robert Grosseteste’sEarly Cosmology”, inMackie and Goering 2003: 135–166 (ch. 6). doi:10.3138/9781442674271-009
• –––, 2012, “The Evolution of the Idea ofCorporeity in Robert Grosseteste’s Writings”, inCunningham 2012: 111–139.
• –––, 2013b, “RobertGrosseteste and Adam of Exeter’s Physics of Light Remarks on theTransmission, Authenticity, and Chronology of Grosseteste’sScientificOpuscula”, inFlood, Ginther, and Goering 2013: 165–190. doi:10.1515/9781771103534-013
• –––, 2017a, “The Scientific Basis ofRobert Grosseteste’s Teaching at the Oxford FranciscanSchool”, inThe English Province of the Franciscans(1224–c.1350), Michael J. P. Robson (ed.), Leiden/Boston:Brill, 247–272.
• –––, 2017b, “Matter and Infinity in RobertGrosseteste’sDe luce andNotes on thePhysics”, inMateria: nouvelles perspectives derecherche dans la pensée et la culture médiévales(XIIe-XVIe siècles), Tiziana Suarez-Nani and AgostinoParavicini Bagliani (eds.), Firenze: SISMEL – Edizioni del Galluzzo,27–55.
• –––, 2018, “The Theological Use of Scienceat the Oxford Franciscan School: Thomas Docking, Roger Bacon, andRobert Grosseteste’s Works”, inThe Franciscan Orderin the Medieval English Province and Beyond (Church, Faith andCulture in the Medieval West), Michael J. P. Robson and Patrick Zutshi(eds.), Amsterdam: Amsterdam University Press, 181–210.
• –––, 2021a, “The Oxford-Paris Connectionof Optics and the Theory of Rainbow: Grosseteste’sDeiride, pseudo-Oresme’sInter omnes impressionesand Bacon’sPerspectiva in Paris, BnF, lat.7434”, inLes Sciences au Moyen Âge (XIIIe-XVesiècle). Autour de Micrologus, Danielle Jacquart andAgostino Paravicini Bagliani (eds.), Florence: SISMEL–Edizionidel Galluzzo, 251–280.
• –––, 2021b, “Adam Rufus of Exeter, Masterand Minor (d. 1234): A State of the Art”, inEarlyThirteenth-Century English Franciscan Thought, Lydia Schumacher(ed.), Berlin: De Gruyter, 93–126.doi:10.1515/9783110684834-005
• –––, 2023, “In the Margins of the‘Posterior Analytics’: Robert Grosseteste and the‘Latin Philoponus’”,Revista Española deFilosofía Medieval, 30(1): 15–52.doi:10.21071/refime.v30i1.16356
• Pickavé, Martin, 2017, “Robert Grosseteste on FreeChoice”, inFrom Learning to Love: Schools, Law, andPastoral Care in the Middle Ages: Essays in Honour of Joseph W.Goering (Papers in Mediaeval Studies 29), Tristan Sharp (ed.),Toronto: Pontifical Institute of Mediaeval Studies, 70–89.
• Polloni, Nicola, 2021a, “Early Robert Grosseteste onMatter”,Notes and Records: The Royal Society Journal of theHistory of Science, 75(3): 397–414.doi:10.1098/rsnr.2020.0017
• –––, 2021b, “Robert Grosseteste on Motion,Bodies, and Light”,British Journal for the History ofPhilosophy, 29(6): 1034–1053.doi:10.1080/09608788.2021.1939651
• Rossi, Pietro, 1995, “Robert Grosseteste and the Object ofScientific Knowledge”, inMcEvoy 1995: 53–76.
• –––, 2012, “Grosseteste’s Influenceon Thirteenth- and Fourteenth-Century British Commentaries onPosterior Analytics”, inCunningham 2012: 140–166.

• Serene, Eileen F., 1979, “Robert Grosseteste on Induction andDemonstrative Science”,Synthese, 40(1): 97–115.doi:10.1007/BF00413947

  [A response to Crombie 1953.]

• Smith, Brett W., 2018, “‘A Theme Song of HisLife’:Aspectus andAffectus in the Writingsof Robert Grosseteste”,Franciscan Studies, 76(1):1–22. doi:10.1353/frc.2018.0000
• –––, 2022, “Scotus and Grosseteste onPhantasms and Illumination”,American Catholic PhilosophicalQuarterly, 96(4): 597–617. doi:10.5840/acpq2022822258
• –––, 2023,‘Aspectus’ and‘Affectus’ in the Thought of Robert Grosseteste,Rome: IF Press.

• Southern, R. W., 1986,Robert Grosseteste: The Growth of anEnglish Mind in Medieval Europe, Oxford: Clarendon Press. Secondedition, 1992.

  [One of the most important works on Grosseteste in recent years. Thesecond edition contains a long reply to some criticisms of the firstedition.]

• Van Dyke, Christina, 2009, “An Aristotelian Theory of DivineIllumination: Robert Grosseteste’sCommentary on thePosterior Analytics”,British Journal for the Historyof Philosophy, 17(4): 685–704.doi:10.1080/09608780902986581
• –––, 2010, “The Truth, the Whole Truth,and Nothing but the Truth: Robert Grosseteste on Universals (and thePosterior Analytics )”,Journal of the History ofPhilosophy, 48(2): 153–170. doi:10.1353/hph.0.0207

• Wallace, William A., 1972,Causality and Scientific Explanation,Volume 1: Medieval and Early Classical Science, Ann Arbor, MI:University of Michigan Press.

  [Chapter 2 discusses Grosseteste’s account of demonstrativescience.]

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