
Euthyphro (fl. 400 BCE) was an ancient Athenian mantis. According to Plato's work Euthyphro, Euthyphro and Socrates engaged in a dialogue about nature of "piety" (virtue). Socrates detected problems with Euthyphro's definition of "piety" causing the mantis to revise his definiton. Eventually, Euthyphro defines "piety" as "What all the gods love". Socrates responds by asking "Is the pious loved by the gods because it is pious? Or is it pious because it is loved by the gods?" Socrates and Euthyphro both contemplate the possibilities and Socrates concludes that Euthyphro's definition doesn't explain the nature of "piety". Socrates' question to Euthyphro would in philosophy later become known as "Euthyphro dilemma".