I lay out and examine two sharply conflicting interpretations of Aristotle's claims about nous in the De Anima (DA). On the human separability approach, Aristotle is taken to have identified reasons for thinking that the intellect can, in some way, exist on its own. On the naturalist approach, the soul, including intellectual soul, is inseparable from the body of which it is the form. I discuss how proponents of each approach deal with the key texts from the DA, focusing on four of the most important and interesting topics in this area. Two of these topics concern the activity of understanding (noesis): first, what does Aristotle mean when he claims that the intellect cannot have a bodily organ and, secondly, what role does Aristotle think phantasmata ("images" or "representations") play in understanding something? Two of the topics concern DA 3.5, one of the most difficult passages in Aristotle's corpus: first, what is the nature and role of the productive intellect (nous poietikos) introduced there and, secondly, what are this chapter's implications for the question of whether the intellect or intellectual soul can exist apart from the body? I conclude by identifying areas where further research is necessary.
