The “right to life” is a venerable moral and legal principle that is regularly invoked in debates about abortion, capital punishment, euthanasia, and more. The philosopher John Locke in his Two Treatises of Government (1690) was the first “modern” theorist to assert the idea of self-evident human rights, including “life, liberty and estate” [i.e., property], while the first public/political assertion of a right to life was in the American Declaration of Independence (1776).