Moral philosopher in the context of "Normative ethics"

Socrates (/ˈsɒkrətiːz/; Ancient Greek: Σωκράτης, romanized: Sōkrátēs; c. 470 – 399 BC) was an ancient Greek philosopher from Classical Athens, perhaps the first Western moral philosopher, and a major inspiration on his student Plato, who largely founded the tradition of Western philosophy. An enigmatic figure, Socrates authored no texts and is known mainly through the posthumous accounts of classical writers, particularly his students Plato and Xenophon. These accounts are written as dialogues, in which Socrates and his interlocutors examine a subject in the style of question and answer; they gave rise to the Socratic dialogue literary genre. Contradictory accounts of Socrates make a reconstruction of his philosophy nearly impossible, a situation known as the Socratic problem. Socrates was a polarizing figure in Athenian society. In 399 BC, he was accused of impiety and corrupting the youth. After a trial that lasted a day, he was sentenced to death. As related by Plato, he was put to death by administration of poison after refusing offers from allies to help him escape.

Plato's dialogues are among the most comprehensive accounts of Socrates to survive from antiquity. They demonstrate the Socratic approach to areas of philosophy including epistemology and ethics. The Platonic Socrates lends his name to the concept of the Socratic method, and also to Socratic irony. The Socratic method of questioning, or elenchus, takes shape in dialogue using short questions and answers, epitomized by those Platonic texts in which Socrates and his interlocutors examine various aspects of an issue or an abstract meaning, usually relating to one of the virtues, and find themselves at an impasse, unable to define what they thought they understood. Socrates frequently proclaims his ignorance, saying that he is only sure that he does not know.

Derek Antony Parfit FBA (/ˈpɑːrfɪt/; 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. His second book, On What Matters (2011), was widely circulated and discussed for many years before its publication.

Peter Albert David Singer (born 6 July 1946) is an Australian moral philosopher who is Emeritus Ira W. DeCamp Professor of Bioethics at Princeton University. Singer's work specialises in applied ethics, approaching the subject from a secular, utilitarian perspective. He wrote the book Animal Liberation (1975), in which he argues for vegetarianism, and the essay "Famine, Affluence, and Morality", which argues the moral imperative of donating to help the poor around the world. For most of his career, he was a preference utilitarian. He revealed in The Point of View of the Universe (2014), coauthored with Katarzyna de Lazari-Radek, that he had become a hedonistic utilitarian.

On two occasions, Singer served as chair of the philosophy department at Monash University, where he founded its Centre for Human Bioethics. In 1996, he stood unsuccessfully as a Greens candidate for the Australian Senate. In 2004, Singer was recognised as the Australian Humanist of the Year by the Council of Australian Humanist Societies. In 2005, The Sydney Morning Herald placed him among Australia's ten most influential public intellectuals. Singer is a cofounder of Animals Australia and the founder of the non-profit organization The Life You Can Save.