The aim of this paper is to assess the central role the imagination acquires in Pierre Gassendi’s logic. I trace the structuring scheme of the three acts of the mind—common to a good number of late scholastic and early modern logics—to the Thomistic notion of the movement of reasoning in knowledge and argue that Gassendi revisits this notion in his logic. The three acts scheme is from the beginning a bridge between logic and the natural philosophical treatment of the soul. I show how Gassendi’s take on the three acts is similarly poised between his Logic and his Physics and I discuss the rationale, sources and consequences of his attribution of the three acts to the imagination. I argue for the following points: Gassendi’s conception of the logical role of the imagination answers to his empiricist epistemology, his naturalized view of the mind (which involves a defense of thinking in animals) and his notion of a natural logic; it is also operative in his pairing of the formal mechanism of logical operations with a progressive mechanism of the operations of the mind; and it serves as a counterpart to his experimental understanding of the progress of knowledge. 1

We propose to read Francis Bacon's doctrine of the idols of the mind as an investigation firmly entrenched in his mental-medicinal concerns and we argue that an important role therein is played by the imagination. Looking at the ways in which the imagination serves to pinpoint several crucial aspects of the idolic mind permits us to signal the explicit or implicit cross-references between what in Bacon's tree of knowledge appear as distinct branches: the various faculties and their arts; the mind, the body, and their league; natural philosophy, moral philosophy, and the philosophy of man. The consequence of this rich picture of the diagnosis of the mind is an equally rich conception of the cure, which comprises both epistemic and physiological aspects. We extract the features of this integrated view out of Bacon's epistemological and medical natural historical writings, which we propose to read in tandem. We also propose a number of sources for Bacon's views on the imagination, whose variety accounts for the multivalent, sometimes elusive, but surely pervasive role of the imagination in the Baconian diagnosis and cure of the mind.