Probably no other issue has engendered more debate in philosophical and scientific discourse than the nature-nurture dichotomy. This entry describes some of the arguments for each side of the dichotomy and the evidence that developmental outcomes are, in fact, the joint product of the coaction of interdependent processes with neither having priority [Page 611]over the other. The idea of separate processes first arose when Plato and Aristotle asked the ultimate epistemological question: What is the origin of human knowledge? In essence, these two philosophers wondered where our ideas of physical objects, causality, number, and space come from. Plato's answer was that our senses do not provide adequate information to form abstract ideas about our world and his “poverty of the stimulus” argument forced him to ...