Journal of the History of Philosophy

Larry Jorgensen aims to show that "Leibniz offers a fully natural theory of mind" (2), recommending Leibniz to our contemporary discussion of naturalism. Readers of Leibniz will, however, hesitate to call him a naturalist. After all, he considered natural laws to be subordinated rules below general divine laws (Discours de métaphysique, §§16–17) and rejected explaining the soul's action by bodily motion. Jorgensen does have a point, though, when he refers to Leibniz's frequent pleas for natural explanations and his continuity principle (1).

Jorgensen's project unfolds in four parts. The first offers a discussion of Leibniz's concept of nature and a clear presentation of Leibniz's principles, above all the often-employed principle of continuity. Part 2 reviews Leibniz's metaphysics of individual [End Page 684] substances in light of his concepts of perception and mental representation. Chapter 5 focuses on Leibniz's concept of expression (106–18), concluding that expression can be described most generally as preserving information (110). This notion (just as those of representation and perception) will serve to emphasize the continuity from simple substances toward souls and up to minds. Jorgensen's central tool is, however, the notion of "perceptive distinctness" (141), which—as opposed to "distinct perception"—allows for all degrees and can thus be ascribed to all substances (123), all expressing God and the universe in different degrees of distinctness. In contrast, distinct perception is seen as a conscious sensation arising from unconscious petites perceptions. Both are distinguished from clear and distinct concepts related to understanding (122). Jorgensen clearly has a point when emphasizing the continuity between different levels of distinctness of perceptions. I wonder, though, if Leibniz would speak of a "bridge from activity to sensation . . . via the bodily mediation of sensation" (131) or of an "activity of the sea on the person" (132–33). Would he not rather refer to the motion of the sea against the person's body? Likewise, "the body's perception" or "the body's perception of the mind" (134) are not expressions that could have been written by Leibniz.

Consciousness is the subject of part 3. Jorgensen is confident that he can question the common understanding of the well-known Leibniz passages about the special quality of minds—the ability to say "I" and to form necessary truths—by referring to Leibniz's principle of continuity and his aim for natural explanations. Consciousness is seen as sensation and "arises by degrees" (141). It depends on a sufficient distinctness of common perceptions (156). Jorgensen discusses the ambiguous use of Leibniz's novel term 'apperception.' While often used for awareness, that is, noticing perceptions unnoticed before, Leibniz uses it also to distinguish the "I" or the person who knows who she is. Jorgensen acknowledges that the texts do not easily support his project but argues that they in any case "underdetermine the interpretation" (159) and could thus well be read in a more continuous, and thus naturalistic, way. Since "memory" is a common way for Leibniz readers to understand his concept of consciousness, Jorgensen suggests a more continuous understanding of it. He distinguishes three levels of memory, labeling them according to terms used by Leibniz, although the latter did not define them as technical terms. All substances express their past and future and have thus a minimal virtual mémoire (177). Animals have réminiscence (conscious perception of prior perceptions being sensation). Minds, though, have souvenir (reflective knowledge of oneself) (182). But aiming for a reduction of consciousness to a certain degree of distinctness of perception, Jorgensen minimizes the role of memory for consciousness, stating, "If perceptional distinctness performs the explanatory role, then it seems metaphysically possible that a single occurrent perception could be strong enough to be conscious" (193–94, emphasis added). This does not fit well with Leibniz's emphasis on the consecutiveness of perceptions needed for awareness and even more for self-consciousness. Chapter 9 is dedicated to appetites. Seeing humans striving for what they consider to...