It is from this standpoint that Leibniz criticises what Locke says about the relation of sensations to the objects which produce them. Leibniz holds that all our sensations have a definite and natural connection with the qualities of objects,—the “secondary” as well as the “primary.” They all represent certain properties of the object. Even the pain which the thrust of a needle gives us, while it does not resemble anything in the needle, does in some way represent or resemble motions going on in our body. This resemblance is not necessarily one of exact form, but just as the ellipse, hyperbola, and parabola are projections of the circle in the sense that there is a natural and fixed law of connection between them, so that every point of one corresponds by a certain relation with every point of the other, so the resemblance between the sensation and the quality of the object is always in the form of a fixed law of order, which, however unknown to us it may now be, is capable of being found out. If we are to make any distinction between “secondary” and “primary” sensations, it should be not that one presents qualities that are in the objects, and the other affections which exist only in us, but that the primary sensations (of number, form, size, etc.) represent the qualities in a distinct way, appealing to the rational activity of intelligence, while the secondary represent the qualities in a confused way, a way not going beyond the effect upon the mind into relations, that is, into distinct knowledge.
This brings regularly before us the question of the relation of sensations to knowledge. We have seen enough already to know that Leibniz does not believe that knowledge begins with the simple (that is, unrelated), and then proceeds by a process of compounding. The sensation is not simple to Leibniz, but thoroughly complex, involving confusedly within itself all possible relations. As relations are brought forth into distinct light out of this confusion, knowledge ends rather than begins with the simple. And again it is evident that Leibniz cannot believe that knowledge begins and ends in experience, in the sense in which both himself and Locke use the word; namely, as meaning the combination and succession of impressions.
“Experience,” as they use the term, consists in sensations and their association,—“consecution” as Leibniz calls it. Experience is the stage of knowledge reached by animals, and in which the majority of men remain,—and indeed all men in the greater part of their knowledge. Leibniz takes just the same position regarding the larger part of our knowledge which Hume takes regarding it all. It consists simply in associations of such a nature that when one part recurs there is a tendency to expect the recurrence of the other member. It resembles reason, but it is based on the accidental experience of events in a consecutive order, and not on knowledge of their causal connection. We all expect the sun to rise to-morrow; but with all of us, excepting the astronomer, such expectation is purely “empirical,” being based on the images of past experiences which recur. The astronomer, however, sees into the grounds, that is, the reasons, of the expectation, and hence his knowledge is rational.
Thus we have two grades of knowledge,—one empirical, consisting of knowledge of facts; the other rational, being of the truths of reason. The former is contingent and particular, the latter is necessary and universal. Leibniz insists, with a pertinacity which reminds us of Kant, that “experience” can give instances or examples only, and that the fact that anything has happened in a given way any number of times in the past, can give no assurance that it will continue to do so in the future. There is nothing in the nature of the case which renders its exact opposite impossible. But a rational truth is necessary, for its opposite is impossible, being irrational or meaningless. This may not always be evident in the case of a complex rational truth; but if it be analyzed into simpler elements, as a geometrical proposition into definitions, axioms, and postulates, the absurdity of its opposite becomes evident. Sensation, in conclusion, is the having of confused ideas,—ideas corresponding to matter. Experience is the association of these confused ideas, and their association according to their accidental juxtaposition in the life of the soul. It therefore is not only thoroughly sensible, but is also phenomenal. Its content is sensations; its form is contingent and particular consecution. Both form and content, accordingly, need to be reconstructed if they are to be worthy of the name of science or of knowledge. This is the position which Leibniz assumes as against the empiricist, Locke. The details of this reconstruction, its method and result, we must leave till we come in the course of the argument again to the subject of knowledge.
Chapter VI.
The Impulses and the Will.
Locke, after discussing the subject of innate ideas in their relation to knowledge, goes on to discuss their practical side, or connection with will. We shall follow him in this as Leibniz does; but we shall consider in connection with this, Leibniz’s general theory of will, which is developed partially in this chapter, but more completely in his critical remarks upon what Locke has to say of the notion of “power.” Since the theory of morals is as closely connected with will as the theory of knowledge is with the intellect, we shall supplement this discussion with what Leibniz says upon the ethical question, drawing our material somewhat freely from his other writings.
The doctrine of will which Leibniz propounds is in closest harmony with his conception of intelligence, and this not merely in the way of empirical juxtaposition, but as the result of his fundamental principles. If we recall what has been said concerning the monad, we shall remember that it is an activity, but an activity with a content. It is a force, but a force which mirrors the universe. The content, that portion of reality which is reflected in the action, is knowledge, or the idea; the activity which brings this about is will, or the volition. They are related to each other as form and content. There is, strictly speaking, no “state” of mind; there is only a tension, a pushing forward of mind. There is no idea which is not a volition. Will is thus used, in a very broad sense, as equivalent to action. Since, however, the activity of the monad is in no case aimless, but has an end in view, the will is not mere activity in general, it is action towards some definite end. And since the end at which the monad aims is always the development of an idea, the reflection of some constituent of the universe, the will is always directed towards and determined by some idea of the intellect.
We have seen, however, that there are various stages in the reflecting power of the soul, or in the realization of intellect. Taking only the broadest division, there are perception and apperception; that is, there are the conscious and the unconscious mirroring of reality. We shall expect, then, to find two corresponding stages of volition. Leibniz calls these stages “appetition” and “volition” in the narrower sense. The constant tendency in every monad to go from one perception to another,—that is, the following of the law of development,—constitutes appetition. If joined to feeling, it constitutes instinct. Since, again, there are two degrees of apperception, one of empirical, the other of rational, consciousness, we shall expect to find two grades of volition proper,—one corresponding to action for conscious particular ends; the other for ends which are proposed by reason, and are hence universal. In this chapter we shall simply expand and illustrate these various propositions.
Sensations, looked at not as to what they represent, but in themselves, are impulses. As such they constitute the lowest stage of will. Impulsive action then includes all such as occurs for an end which is unknown, or at best but dimly felt. Such action may be called blind, not in the sense that it is without reason, but in the sense that reason is not consciously present. We are not to think of this instinctive action, however, as if it were found simply in the animals. Much of human action is also impulsive; probably, indeed, an impulsive factor is contained in our most rational willing. We