Having sketched the views of the predecessors and why they hold them, Aristotle criticizes them for the rest of book 1. This is Aristotle's version of Socratic cross-examination. Chapters 3 and 4 challenge the views of those explaining the soul as mover in motion; chapter 5 attacks those focusing upon the soul's role in cognition. Cognition enters chapter 3 to some extent as well, because cognition may be a sort of motion. The soul might be in motion either because as mover of the animal it has motion of its own that originates motion in the body or because cognition is some sort of motion. This prominence of motion helps explain why 405b31 announces that soul's involvement with motion should be considered first (cf. 403b27–29). All the criticism of predecessors will be dialectical. Aristotle cannot simply demonstrably refute the endoxa but only argue against them on the basis of other endoxa. Dialectic lacks firm starting points, instead using some endoxa to challenge others. Yet in spite of being dialectical, Aristotle's arguments end up with the definitive conclusion that the predecessors' positions are impossible (see, e.g., 405b31–406a3). How can such a solid conclusion emerge from dialectical consideration?

Aristotle, it will be seen, uses a barrage of arguments. It may well provoke suspicion that so many arguments enter the attack against his predecessors' views. Were there a decisive argument, we might expect it to suffice, but Aristotle frequently resorts to a series of arguments. Plato's Socrates occasionally does much the same himself.