Current debates on human rationality are divided between what Matthew Boyle calls the additive and transformative approaches. My concern is not with the current debate, but with Boyle’s alignment of Descartes and Aristotle with the modern approaches, directing his criticisms against the former, and his defence in support of the latter. What motivates my enquiry is whether Boyle’s use of the two philosophers’ theses stands up to scrutiny and consequently whether his alignments are cogent. I focus primarily on Descartes’ position, (...) examining Boyle’s criticisms. Towards the end, I turn to Aristotle’s position and raise two central questions omitted by Boyle. (shrink)