Michael H. Otsuka (born 1964) is an American^[2]left-libertarian political philosopher and Professor in the Department of Philosophy atRutgers University.^[3]

Otsuka earned hisDoctor of Philosophy degree inpolitics fromBalliol College, Oxford, under the direction ofG. A. Cohen, on aMarshall Scholarship, after graduating fromYale University with a bachelor's degree inpolitical sciencesumma cum laude in 1986.

Prior to moving to theLondon School of Economics in 2013, Otsuka was Professor ofPhilosophy atUniversity College London, where he had taught since 1998,^[3] and, before that taught atUCLA and theUniversity of Colorado. He joined Rutgers University in September 2022.^[4]

Otsuka has written extensively inpolitical philosophy on topics such asequality andleft-libertarianism. Otsuka is a proponent ofactual-consent forms of government, in opposition to the mainstream of political theory which has thought such systems to be unworkable. He has also published articles innormative ethics on the morality of harming and saving from harm.

Otsuka also defends what is known as "equal opportunity left-libertarianism", which interprets

theLockean proviso requiring that one leave enough for others to have an opportunity for well-being that is at least as good as the opportunity for well-being that one obtained in using or appropriating natural resources. Individuals who leave less than this are required to pay the full competitive value of their excess share to those deprived of their fair share.^[5]

One of Otsuka's most influential articles—cited and critiqued byJeff McMahan in his own workThe Ethics of Killing—is "Killing the Innocent in Self-Defense" (Philosophy & Public Affairs, 1994) In this article, Otsuka develops what he calls the Moral Equivalence Thesis, according to which Innocent Threat (e.g., the body of Falling Person is about to kill you by crushing you to death but who was thrown off the top of a building by an evil Villain) is on a moral par with Bystander, or one who is not at all responsible for whatever endangers your life. Imagine a javelin is heading toward you and will kill you unless you pull Bystander into its path so it kills Bystander instead. Because it would be morally impermissible to kill Bystander in this way, it would also be morally impermissible for you to kill Falling Person by, say, vaporizing him with a ray gun. Further, it is morally impermissible to kill an Innocent Aggressor, or someone who endangers your life because of her intention to kill you but whose actions are beyond her control. Imagine someone who has been hypnotized and whose aim is to kill you. It is wrong to kill Innocent Aggressor because he is on a moral par with Innocent Threat, who is on a par with Bystander. So, it is wrong to kill Innocent Aggressor because he is on a par, morally, with Bystander.

• Libertarianism Without Inequality (2003)

• Michael Otsuka's homepage

• 1964 births
• Academics of the London School of Economics
• Academics of University College London
• Alumni of Balliol College, Oxford
• American expatriates in the United Kingdom
• American libertarians
• American male non-fiction writers
• American political philosophers
• Left-libertarians
• Libertarian theorists
• Living people
• Marshall Scholars
• Writers from Palo Alto, California
• University of California, Los Angeles faculty
• University of Colorado Boulder faculty
• Yale College alumni
• American academics of Japanese descent

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