Euthyphro of Prospalta (/ˈjuːθɪfroʊ/; Greek: Εὑθύφρων Προσπάλτιος, Euthύphrōn Prospáltios; fl. 400 BCE) was an ancient Athenian religious prophet (mantis) best known for his role in his eponymous dialogue written by the philosopher Plato. The debate between Euthyphro and Socrates therein influenced generations of theologians and gave rise to the question of the relationship between God and morality known as the Euthyphro dilemma.