During the seventeenth century the major cognitive faculties--sense, imagination, memory, and understanding or intellect--became the central focus of argument in metaphysics and epistemology to an extent not seen before. The theory of the intellect, long an important auxiliary to metaphysics, became the focus of metaphysical dispute, especially over the scope and powers of the intellect and the existence of a `pure' intellect. Rationalist metaphysicians such as Descartes, Spinoza, and Malebranche claimed that intellectual knowledge, gained independently of the senses, provides the (...) framework for constructing a new theory of nature. Other writers, including Hobbes and the early Gassendi, denied the existence of a distinct intellectual faculty, and so challenged the metaphysicians' abilities directly to perceive the essences of substances. The theory of the senses, which had long been a part of philosophical discussion, took on a new urgency, for adherents of the new corpuscularian philosophy needed to replace the dominant Aristotelian theory of real sensory qualities and sensible species. The revival of skepticism and a renewed interest in method also brought the faculties into prominence, for skeptical challenges typically were directed toward the faculties of sense and understanding, and the theory of method was conceived as providing instructions for the proper use of one's cognitive equipment. The theory of the faculties, then, is an important key to theories of knowledge in the seventeenth century. Indeed, rather than speaking of seventeenth century epistemology, it would be less anachronistic and more informative to speak of theories of cognition. The familiar (and over-stated) point that epistemology became fundamental to metaphysics during that century can then be restated as the point that the theory of faculties became central in metaphysical dispute. (shrink)