in his writings he was happy to insert his own views into Socrates's words. Under this understanding, there is a distinction between the Socratic Socrates of Plato's earlier works and the Platonic Socrates of Plato's later writings, although the boundary between the two seems blurred. Xenophon's and Plato's accounts differ in their presentations of Socrates as a person. Xenophon's Socrates is duller, less humorous and less ironic than Plato's. Xenophon's Socrates also lacks the philosophical features of Plato's Socrates—ignorance, the Socratic method or elenchus—and thinks enkrateia (self-control) is of pivotal importance, which is not the case with Plato's Socrates. Generally, logoi Sokratikoi cannot help us to reconstruct the historical Socrates even in cases where their narratives overlap, as authors may have influenced each other's accounts. Aristophanes and other sources Writers of Athenian comedy, including Aristophanes, also commented on Socrates. Aristophanes's most important comedy with respect to Socrates is The Clouds, in which Socrates is a central character. In this drama, Aristophanes presents a caricature of Socrates that leans towards sophism, ridiculing Socrates as an absurd atheist. Socrates in Clouds is interested in natural philosophy, which conforms to Plato's depiction of him in Phaedo. What is certain is that by the age of 45, Socrates had already captured the interest of Athenians as a philosopher. It is not clear whether Aristophanes's work is useful in reconstructing the historical Socrates. Other ancient authors who wrote about Socrates were Aeschines of Sphettus, Antisthenes, Aristippus, Bryson, Cebes, Crito, Euclid of Megara, Phaedo and Aristotle, all of whom wrote after Socrates's death. Aristotle was not a contemporary of Socrates; he studied under Plato at the latter's Academy for twenty years. Aristotle treats Socrates without the bias of Xenophon and Plato, who had an emotional tie with Socrates, and he scrutinizes Socrates's doctrines as a philosopher. Aristotle was familiar with the various written and unwritten stories of Socrates. His role in understanding Socrates is limited. He does not write extensively on Socrates; and, when he does, he is mainly preoccupied with the early dialogues of Plato. There are also general doubts on his reliability on the history of philosophy. Still, his testimony is vital in understanding Socrates. The Socratic problem In a seminal work titled "The Worth of Socrates as a Philosopher" (1818), the philosopher Friedrich Schleiermacher attacked Xenophon's accounts; his attack was widely accepted and gave rise to the Socratic problem. Schleiermacher criticized Xenophon for