Page:Mind (Old Series) Volume 11.djvu/101

 90 J. M. RIGG : since it can only be denned as the termination of a line. Hence by a somewhat unhappy metaphor the monads are designated metaphysical points, pure, i.e., perfectly abstract units. The monad however is not merely one and indivisible ; it is also active and percipient. Of perception no distinct account is given. It is not a passive affection of the monad, for that is inaccessible to any influence except that of the uncreated monad, God : its nature is wholly active. Accordingly perception is vaguely described as " the transitory state in which a multitude is embraced and represented in unity or in the simple substance," as " a reflection of the universe " due solely to the spontaneous activity of the monad and varying in adequacy according to the degree of that activity. God is not invoked to explain the origin of perception, but He is represented as exalting and depressing the activity now of this now of the other monad, so as to give an appearance of action and reaction between them. 1 An attempt is made to explain the transition from one perception to another by a vague reference to an internal principle of " appetition," a kind of final causality. The net result is a jumble of incompatible ideas, a unit which is wholly secluded in its abstract unity yet reflects a manifold universe, and does so in virtue of its own activity, modified by the activity of the nova* novdcwv- Leibniz indeed evaded the absurdity (on which Aristotle insists as against Xeno- crates) inherent in supposing a unit to move or be moved, by his hypothesis of a preestablished harmony between the " appetites" of the monad and the system of efficient causes, so that every perception of the monad has its correlative physical movement ;- but it is as absurd to predicate activity of a unit as to predi motion of it, and just because the soul is active it cannot be a unit. Number, as Aristotle points out at a later stage, is one of the common perceptions, and therefore no idea derived from number, however subtly disguised its derivation may be, can do duty as a definition of the perceptive faculty. 3 Another form of the arithmetical theory of the soul no less absurd than that of Leibniz is that which identifies it with the series of its states. A series of course is a number, and to define the soul as a series of feelings aware of itself as a series is in fart to define it as a self-conscious number. The number, the series of states, exists only for the soul in its reflection upon itself ; so that the definition is a i'(n/n>i> vpn-epoi-. Aristotle concludes his review of his predecessors by examining the theory of perception advanced by Empedocles. This theory, based on the principle in itself true that like is only perceivable li like, is nevertheless so crude that it is chietly interesting because of the light which Aristotle's method of refuting it sheds fil. Knluiuim, pp. 705-6, 709, 74.">. " /////.. p. 714. 8 De An., ii. 6.