There is prima facie evidence that Theophrastus naturalized nous to the extent that he spoke of it in naturalizing terms. But our evidence also suggests that Theophrastus accepted the reasons Aristotle had for excluding nous from the reach of natural philosophy. We show that, far from revealing an inconsistency on Theophrastus’ part, this apparent tension results from a consciously adopted strategy. Theophrastus is developing one aspect of Aristotle’s account of nous he found underdeveloped and feared might be misunderstood, namely the (...) infrangible organic unity of the whole human being, including its nous. That is why he insists that nous, although ‘from outside,’ is ‘grown together’ with us, why he speaks of it as a nature (phusis), and why he insists that thought is a motion (kinêsis). We show how these striking claims can be understood against the broader background of Theophrastus’ natural philosophy. (shrink)