such as the purpose of life or the nature of arete (virtue), since Socrates had not handed them an answer, and therefore, philosophical schools subsequently diverged greatly in their interpretation of his thought. He was considered to have shifted the focus of philosophy from a study of the natural world, as was the case for pre-Socratic philosophers, to a study of human affairs. Immediate followers of Socrates were his pupils, Euclid of Megara, Aristippus, and Antisthenes, who drew differing conclusions among themselves and followed independent trajectories. The full doctrines of Socrates's pupils are difficult to reconstruct. Antisthenes had a profound contempt of material goods. According to him, virtue was all that mattered. Diogenes and the Cynics continued this line of thought. On the opposite end, Aristippus endorsed the accumulation of wealth and lived a luxurious life. After leaving Athens and returning to his home city of Cyrene, he founded the Cyrenaic philosophical school which was based on hedonism, and endorsing living an easy life with physical pleasures. His school passed to his grandson, bearing the same name. There is a dialogue in Xenophon's work in which Aristippus claims he wants to live without wishing to rule or be ruled by others. In addition, Aristippus maintained a skeptical stance on epistemology, claiming that we can be certain only of our own feelings. This view resonates with the Socratic understanding of ignorance. Euclid was a contemporary of Socrates. After Socrates's trial and death, he left Athens for the nearby town of Megara, where he founded a school, named the Megarians. His theory was built on the pre-Socratic monism of Parmenides. Euclid continued Socrates's thought, focusing on the nature of virtue. The Stoics relied heavily on Socrates. They applied the Socratic method as a tool to avoid inconsistencies. Their moral doctrines focused on how to live a smooth life through wisdom and virtue. The Stoics assigned virtue a crucial role in attaining happiness and also prioritized the relation between goodness and ethical excellence, all of which echoed Socratic thought. At the same time, the philosophical current of Platonism claimed Socrates as its predecessor, in ethics and in its theory of knowledge. Arcesilaus, who became the head of the Academy about 80 years after its founding by Plato, radically changed the Academy's doctrine to what is now known as Academic Skepticism, centered on the Socratic philosophy of ignorance. The Academic Skeptics competed with the