vague approximation of them, are expressed in Plato's early socratic dialogues. Meanwhile, other scholars have argued that Plato's portrayal of Socrates is merely a fictional representation intended to expound Plato's own opinions who has very little to do with the historical figure of the same name. The debate over the extent to which Plato's portrayal of Socrates represents the actual Socrates's ideas is known as the Socratic problem. Plato expressed his ideas through dialogues, that is, written works purporting to describe conversations between different individuals. Some of the best-known of these include: The Apology of Socrates, a purported record of the speech Socrates gave at his trial; Phaedo, a description of the last conversation between Socrates and his disciples before his execution; The Symposium, a dialogue over the nature of love; and The Republic, widely regarded as Plato's most important work, a long dialogue describing the ideal government. Aristotle of Stagira is widely considered to be one of the most important and influential philosophical thinkers of all time. The first sentence of his Metaphysics reads: "All men by nature desire to know." He has, therefore, been called the "Father of those who know." His medieval disciple Thomas Aquinas referred to him simply as "the Philosopher". Aristotle was a student at Plato's Academy, and like his teacher, he wrote dialogues, or conversations. However, none of these exist today. The body of writings that have come down to the present probably represents lectures that he delivered at his own school in Athens, the Lyceum. Even from these books, the enormous range of his interests is evident: He explored matters other than those that are today considered philosophical; the extant treatises cover logic, the physical and biological sciences, ethics, politics, and constitutional government. Among Aristotle's most notable works are Politics, Nicomachean Ethics, Poetics, On the Soul, and Rhetoric. Hellenistic period By 338 BC all of the Greek city-states except Sparta had been united by Philip II of Macedon. Philip's son Alexander the Great extended his father's conquests greatly. Athens lost its preeminent status as the leader of Greek culture, and it was replaced temporarily by Alexandria, Egypt. The city of Alexandria in northern Egypt became, from the 3rd century BC, the outstanding center of Greek culture. It also soon attracted a large Jewish population, making it the largest center for Jewish scholarship in the ancient world. The Septuagint, a Greek translation of the