Aristotle did not title his work Metaphysics. Some three centuries after his death, a Roman editor named Andronicus collected the chapter that make up the book and gave them this title. Aristotle's Metaphysics defined its field in many ways. But it also has roots in previous philosophical tradition. English philosopher Anthony Kenny notes that, "most dissertations that begin with literature searches seek to show that all work hitherto has left a gap that will now be filled by the author's original research. Pre-Socratic ideas, therefore, provided a rich intellectual soil in which Aristotle could develop his own views. Aristotle's most important influence was probably his teacher Plato. Aristotle studied in Plato's Academy for two decades, so it stands to reason that his intellectual relationship with the elder philosopher shaped his own development. Aristotle is known for criticizing Platonic ideas. But although cannot say exactly how Plato influenced Aristotle, it is clear that on the whole he was a positive influence.