Derek Parfit’s ‘triple theory’ In his monumental and ambitious two volume work, On What Matters, Derek Parfit seeks to show that, suitably interpreted, t hree popular ethical theories—rule consequentialism, contractualism, and Kantianism —can be seen as not only compatible but mutually supporting. Henry Sidgwick Immanuel Kant Christine Korsgaard John Stuart Mill Thomas Nagel. Derek Parfit, pictured at Oxford in 2015, published seldom, but his works of philosophy were ambitious and influential. Parfit incorporates Kant and contractualism as two parts of his Triple Theory. In the first two volumes of On What Matters, Derek Parfit argues that three major normative theories – Kantianism, Contractualism and Rule Consequentialism – are, in their most defensible forms, compatible, and can be reconciled in what he calls ‘Triple Theory’.This has led many to assume that Parfit does not believe that Act Consequentialism is a defensible form of Consequentialism. The central claim of On What Matters is Parfit’s proposal of the “Triple Theory.” It attempts to characterize the wrongness of acts. 1. I, p. 413). Parfit believed he had demonstrated that his ‘triple theory’ was just such a non-subjective set of moral principles. Triple Theory; Influences. On What Matters by Derek Parfit ... Parfit’s eventual Triple Theory of morality is that “an act is wrong just when such acts are disallowed by some principle that is optimific, uniquely universally willable, and not reasonably rejectable.” (Vol. Influenced. The second theme concerns the notion of a normative reason. Derek Antony Parfit FBA (/ ˈ p ɑːr f ɪ t /; 11 December 1942 – 1 January 2017) was a British philosopher who specialised in personal identity, rationality, and ethics.He is widely considered one of the most important and influential moral philosophers of the late 20th and early 21st centuries. I, p.413) This is as titanic a theory as one could hope for in … Parfit calls the common ground between what he argues are the best versions of each of Kantianism, Consequentialism, and Contractualism the Triple Theory. Einleitung: Parfits triple theory der Moral. Derek Parfit (11 December 1942 – 1 January 2017) was a British philosopher. But then he insists, with little argument beyond his intuitive responses to Trolley-like examples, that the very rules that are justifiable to all, and to which all could rationally consent, are … John Cottingham Sam Harris (author) Effective Altruism. December 2016; Zeitschrift für Praktische Philosophie 3(2):177-184; DOI: 10.22613/zfpp/3.2.6 Parfit calls the common ground between what he argues are the best versions of each of Kantianism, Consequentialism, and Contractualism the Triple Theory. They can all agree on the Triple Theory, as Parﬁt calls it, according to which, roughly, “an act is wrong just when such acts are disallowed by some principle that is optimiﬁc, uniquely universally willable, and not reasonably rejectable” (Parﬁt, 2011, vol.