Derek Antony Parfit (; 11 December 1942 – 2 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. Parfit rose to prominence in 1971 with the publication of his first paper, "Personal Identity". His first book, Reasons and Persons (1984), has been described as the most significant work of moral philosophy since the 1800s.
https://en.wikipedia.org/wiki/Derek_Parfit