Erick Raphael Jiménez. Aristotle's Concept of Mind. Cambridge: Cambridge University Press, 2017. Pp. vii + 265. Cloth, $99.99. In this ambitious first book, Erick Raphael Jiménez argues that a good model for understanding Aristotle's concept of mind (nous) lies in Aristotle's account of the perception of time. This "time-perception model" of mind and its activity, thinking, bridges a gap between Jiménez's unorthodox readings of Aristotelian mind and its objects. The book will attract the interest of specialists in Aristotle's psychology, as well as other scholars interested in Aristotle's concept of mind and its influence, for instance, theologians interested in Aristotle's tantalizing discussion of active or maker mind in De Anima 3.5 (DA). The book mainly focuses on the many seemingly intractable difficulties in DA 3.4–7, although three of the book's nine chapters take necessary interpretive detours: into Metaphysics 7 and Posterior Analytics 2.19 (to discuss essences and principles as objects of mind), and into Physics 4 (to explain Aristotle's concept of time). But the heart of Jiménez's discussion is certainly DA 3.5. Jiménez says we have "reason to suspect" that the discussion of active mind "comprises, in one way or another, the real core of Aristotle's thinking about mind" (32). He therefore devotes his longest chapter to a close commentary on that discussion. Jiménez argues that, "Active mind makes something thinkable, and passive mind thinks it" (85), where active mind is one aspect of mind in general-one that is neither divine nor immortal (not literally). Like other psychological functions, mind is embodied, especially because of its reliance on something else that is clearly embodied, namely phantasia (66). One of the book's central contentions is that, for Aristotle, mind is an accomplishment, an intellectual virtue. Jiménez rejects the idea that mind is (like sensation, aisthēsis) an innate human faculty. He argues that, for Aristotle, individual human beings have no potential for thinking in advance of actual thinking. Individual humans will therefore lack-in advance of actual thinking, let alone achieving what Jiménez calls "success in explanation" (3)-the intellectually virtuous state of mind. Jiménez expresses this actuality-first view by saying that Noell Birondo. Journal of the History of Philosophy 57:1 (2019) 162–163 "humans are not born with minds" (113). But what this actually means is that humans are not born with this one highly specific intellectual virtue. Jiménez's view will provoke incredulous reactions from the many contemporary commentators who take Aristotle to endorse explicitly, at the beginning of DA 3.4, an analogy between thinking and sensing. Jiménez argues, on the contrary, that Aristotle considers that analogy only to draw out its absurd consequences. The incredulous reactions overlook the fact that, in the passage in question (DA 3.4 429a13–429b9), Aristotle is "demonstrating the incoherence of the supposition that thinking is like sensing" (18). Jiménez devotes his opening chapter, one of the book's shortest, to defending this unorthodox reading. On the other side of the orthodox "abstractionist" interpretation, the world is potentially intelligible in advance of actual human thinking, just as visible objects (say) are potentially sensible in advance of actual human sensing. But having rejected the analogy between thinking and sensing, Jiménez argues that this too is a mistake. In the beginning, humans are unintelligent, and the world is unintelligible (5). The time-perception model is meant to bridge the epistemological gap here. It does so by insisting that, unlike the ability to think, humans are born with the ability to perceive time. And Jiménez says that "the ability to perceive time is the innate ability through which we develop the ability to think" (162). This stepping-stone allows Jiménez to defend the interesting idea that in DA 3.6–7, Aristotle provides "a more specific account" (190, my emphasis) of the active and passive aspects of thinking discussed in DA 3.5. The resulting position is complex. Jiménez puts the main idea by saying that: "mind qua constructive posits a unity in terms of relations of priority and posteriority, and mind qua passive perceives their coherence" (190). He also says that: "Mind as maker attempts to construct causal sense of the world, and mind as 'receiver' attempts to assess the validity of those constructions" (215–16). Part of the idea here is that thinking (like the perception of time) is perception of a medium joining prior to posterior (201). Jiménez says that when we think different thoughts, "we are discerning different inferential relations" (208)-relations with the structure "y follows x," in Aristotle's causal-explanatory sense of "following" (akolouthein, 162). Thus when a biologist explains the long gestation period of elephants (213), she actively posits the elephant's size as prior to its long gestation, since the gestation follows from the size-and she passively perceives this thought's coherence. This reconstruction will give a sense, I hope, of the most difficult and original idea in this difficult and original book. I am not sure what to think about its explanations of Aristotle's text, but I am sure that time will tell. NOELL B IRONDO Wichita State University