  In chapter 5, Aristotle distinguishes two types of opponent, those who claim to reject PNC for the sake of argument, and those Pre-Socratics who are genuinely perplexed. He now addresses the second type. Anaxagoras and Democritus are led to say that contradictions are true at the same time, because they are confused by change. They see contraries coming into existence out of the same thing, and infer that the same thing must have had contrary properties. Aristotle introduces his distinction between the potential and the actual to dispel their confusion. An object can be potentially F and potentially not F, but it cannot be actually F and actually not F at the same time.