Journal of the History of Philosophy

Leibniz and Degrees of Perception ROBERT B. BRANDOM THE CONCEIT OF REPRESENTATION is at the center not only of seventeenthcentury theories of knowledge but of their corresponding ontologies as well. Descartes was impressed and illuminated by mathematical innovations that enabled, on the one hand, a precise geometrical account of the optical transformations of figures and images in vision and, on the other, the formally adequate representation of such geometrical situations by nonspatial, discursive expressions in coordinate algebras. God aside, the real was for him accordingly divided into the purely geometrical realm of extension and the realm of thought (taking algebra as its model), which represents what is extended. Leibniz, with a reservation of profound consequence for subsequent German idealism, would deny metaphysical reality to what is representable but not itself a representing. Defining perception as the representation or expression of the many in the one, l Leibniz adumbrates a metaphysical system whose primary features follow from the doctrine that to be is to perceive. Put in his inherited terminology, monads alone are true subAbbreviations D "Discourse on Metaphysics," in G, 4:422-63. Translations herein are from G. W. Leib'aiz: Philosophical Papers and Letters, trans. L. E. Loemker, 2rid ed., 2 vols. (Dordrecht: D. Reidel, 1969); cited by section numbers. G Die philosophischen Schriften yon G. W. Leibniz, ed. C. I. Gerl~ardt, 7 vols.(Berlin, 1875-9o). GM Die mathematischen Schriften yon G. W. Leibniz, ed. C. I. Gerhardt, 7 vols. (Berlin and Halle, 1849-63). M "Monadology," in G, 6:6o7-23 (translations herein from Loemker); cited by sec. nos. NE New Essays concerning Human Understanding, trans. A. G. Langley, 3rd ed. (LaSalle, I11.: Open Court, 1949); I have emended the translation herein where necessary; cited by sec. and p. nos. PNG "Principles of Nature and Grace," in G, 6:598-6o6 (translations herein from Loemker); cited by sec. nos. G, 2:a21,311; 3:69, 574; 6:598, 6o8; 7:317,529 . [4471 448 HISTORY OF PHILOSOPHY stances, and perception is their fundamental attribute. Perceivings, the modifications of substances in that attribute,' are monadic properties. Relations , for example, spatial ones, cannot be perceivings, but are rather merely perceivable, as features of the multiplicity that is unified in a single perception . As nonperceiving creatures of perception, space, time, and matter--no less than color and odor--are relegated to the second-class metaphysical status of "true phenomena. ''3 To understand Leibniz's version of reality as a privileged class of representings 4 we must understand four features of his account of perception. First, the genus of which perception is a species is that of expression or representation . Leibniz says generally, "One thing expresses another.., when there is a constant and regulated relation between what can be said of the one and of the other. ''5 Favorite examples are the relations between a map and the corresponding geographical region and between a minature model of a machine and the machine itself. Second, as noted above, the specific difference defining perceptual representations is that in perception a multiplicity is expressed in a unity. Third, each monad (indeed, each set of contemporaneous perceptions of any monad) expresses its whole world6---the "flower in the crannied wall" doctrine occasionally glossed by the claim that a perfect intelligence could deduce every feature of the universe from the consideration of the perceptions of a single monad. Fourth, perception comes in degrees, variously referred to as degrees of perfection or distinctness. The last of these features is of cardinal metaphysical importance, since it is explanatorily responsible both for the diversity of points of view of the monads and for the preestablished harmony between them that is Leibniz's systematic synthesis of the principles of unity and of maximal multiplicity. Leibniz explains the relation between the diversity of monadic perspectives and the expression by each of its whole world in the Monadology: [A] The nature of the monad being to represent, nothing can limit it to representing only a part of things, though it is true that its representation is merely confused as to the details of the whole universe, and can be distinct for a small part of things only, ' I ignore here appetitions...