bards who conveyed Greek mythology), who attributed natural phenomena to the gods. The term was coined to highlight a fundamental change in philosophical inquiries between the philosophers who lived before Socrates, who were interested in the structure of nature and cosmos (i.e., the universe, with the implication that the universe had order to it), and Socrates and his successors, who were mostly interested in ethics and politics. The term comes with drawbacks, as several of the pre-Socratics were highly interested in ethics and how to live the best life. Further, the term implies that the pre-Socratics are less significant than Socrates, or even that they were merely a stage (implying teleology) to classical era philosophy. The term is also chronologically inaccurate, as the last of the pre-Socratics were contemporaries of Socrates. According to James Warren, the distinction between the pre-Socratic philosophers and philosophers of the classical era is demarcated not so much by Socrates, but by geography and what texts survived. The shift from the pre-Socratic to the classical periods involves a shift from philosophers being dispersed throughout the Greek-speaking world to their being concentrated in Athens. Further, starting in the classical period we have complete surviving texts, whereas in the pre-Socratic era we have only fragments. Scholar André Laks distinguishes two traditions of separating pre-Socratics from Socratics, dating back to the classical era and running through current times. The first tradition is the Socratic-Ciceronian, which uses the content of their philosophical inquires to divide the two groups: the pre-Socratics were interested in nature whereas Socrates focused on human affairs. The other tradition, the Platonic-Aristotelian, emphasizes method as the distinction between the two groups, as Socrates moved to a more epistemological approach of studying various concepts. Because of the drawbacks of the term pre-Socratic, early Greek philosophy is also used, most commonly in Anglo-Saxon literature. Sources Very few fragments of the works of the pre-Socratic philosophers have survived. The knowledge we have of the pre-Socratics derives from the accounts of later writers such as Plato, Aristotle, Plutarch, Diogenes Laërtius, Stobaeus, and Simplicius, and some early Christian theologians, especially Clement of Alexandria and Hippolytus of Rome. Many of the works are titled Peri Physeos, or On Nature, a title probably attributed later by other authors. These accounts, known as testimonia (testimonies), often come from biased writers. Consequently, it is sometimes difficult to determine the actual line of argument some pre-Socratics used