To illustrate more particularly the nature and sphere of perception, as the term is used in the Cartesian school, it is necessary to attend to the division of the phenomena of consciousness, adopted by Descartes, and current among his followers. Descartes divides all our thoughts (cogitationes)—and with him thought is the general name for each mode or phenomenon of consciousness—into two grand classes, viz., the Activities and Passivities of mind (actiones et passiones sive affectus animae), the distinguishing element of these two classes being, that in the former case the mind of itself determines its own modification; in the latter it is determined to it, by some action, to wit, foreign from the will. The first class embraces all the acts of the will, or the volitions (volitiones sive operationes voluntatis), inasmuch as all such modifications of mind are considered by him as determinable, and actually determined, by the power of free choice or will, i.e., by the mind itself; and under volition (i.e., to use the language of his followers, latio quaedam anim tendens ad objectum in idea propositum) he comprehends judgment and will proper (velle et nolle), according as the object is regarded under the notions of the true and the false, or of the good and the bad. To the second class he refers all the cognitive acts of the mind, considered merely as apprehensive of their objects (perceptiones sive operationes intellectus), inasmuch as our apprehensions are not made arbitrarily, or at the pleasure of our will, but determined by their objects, and are thus, in a sense, passions or passivities. In this way all the acts, whether of sense, memory, imagination, or the pure intellect, are but different modes of perceiving; for in each we only know as we are conscious of, or apprehend, the object of the act. Further, as each mental modification has a reality for us only in so far as we actually apprehend or are conscious of it, it is plain that, in every actual mode of mind, there is involved a consciousness, or, in the Cartesian language, a perception; and thus we are said to perceive not only when in sense we apprehend by idea or representation extension or figure—the qualities of somewhat lying beyond ourselves, or the representative object in imagination, but likewise when we are conscious of the forth-putting of an act of will or of being affected by joy or hope. More particularly as, according to the Cartesian doctrine, the consciousness of a modification of mind, a volition, for example, is, though in thought (ratione) separable, not really distinct from this modification itself, all modes of mind whatsoever, as participating of consciousness, are, in a sense, perceptions; for this implies nothing more than that they exist in consciousness. In this sense perception is not contrasted with, but comprehends volition, though extending further. As some modifications of mind, however, though only manifesting themselves through knowledge, are yet not apprehension simply or even knowledge, but to use his own phrase, have other forms, as volition, we may consider them in reference to these other characters; and as, on the Cartesian doctrine, these characters are negative of each other, we thus obtain classes not only in opposition, but in fundamental contrast. These distinguishing characteristics are, as we have seen, the qualities of activity and of passivity, which thus afford two grand divisions of the mental modifications, called respectively volitions and perceptions.
That perception was only logically discriminated from its object on the doctrine of Descartes, will be manifest from what follows:—
“I observe (he says) that whatever is done, or recently happens, is generally called by the philosophers passion, in respect of the subject to which it happens, and action in respect of that which causes it to take place, so that, although agent and patient are often very diverse, action and passion nevertheless remain one and the same thing, having these two names by reason of the two different subjects to which it can be referred.”—De Pass., P. I, art. 1.
“Our perceptions are of two species: some have the mind for their cause, and others the body. Those that have the mind for their cause are the perceptions of our volitions, and of all our imaginations that depend on it; for it is certain that we cannot will anything without perceiving
