or both. While in the perception of roughness, the like sensations of motion are known as simultaneous with a broken series of sensations of touch, or pressure, or both.

It is unnecessary thus to analyze our perceptions of all the statico-dynamical attributes above enumerated. What has been said renders it sufficiently manifest, that they severally consist in the establishment of relations of simultaneity and sequence among our sensations of touch, pressure, tension and motion; experienced as increasing, decreasing, or uniform; and combined in various modes and degrees. This is all which it here concerns us to know.

§ 325. Passing from these preliminary analyses to the general subject of the chapter-the perception of body as presenting statico-dynamical and statical attributes, we find that it is made up of the following elements. The relations of coexistence in time and adjacency in space between subject and object; the combined impressions which make up our ideas of a more or less specific size and a more or less specific shape; the further impressions included in our notions of surface; those included in our notions of texture; and those many others signified by the terms ductility, elasticity, flexibility, &c.: all of them referred to a place in space that is approximately the same, and to a time that is common to them all.

Merely re-stating these several constituents of the perception, which were to some extent incidentally described in the last chapter, it remains to specify more definitely than before, the kind of union subsisting among them. When in the dark the presence of some object is revealed by accidental collision, we have, along with certain unexpected sensations of pressure and muscular tension, a vague conception of a something extended; and, as previously explained, this relation of coexistence between resistance and extension is unconditional-is independent alike of the will of the subject and the quality of the object.

The

special elements of the perception are conditional. If the nature of the object is to be ascertained, its reactions must be called forth by certain appropriate actions of the subject. The sensations it gives us must become known as sequent to certain sensations we give ourselves. There must be particular kinds of volition and the particular changes of internal state that follow them, before the changes resulting from external impressions can be received. It is true that some of the resistance-attributes, as hardness and softness, usually become involuntarily known in the act of collision; though this is not necessary, since, when moving with out-stretched hands, the gentlest touch suffices to prove the existence of something, before yet we can know aught of its nature. But to determine whether the body is rough or smooth, flexible or rigid, ductile or inductile, implies correlative subjective activities of a complicated kind; and the modifications of consciousness accompanying these, must become essential elements of the perceptions. Hence, a statico-dynamical attribute is perceived through a union of internally-determined impressions with externallydetermined impressions; which combined group of impressions is known as the consequent of those internally-determined changes constituting volition.

Defined in its totality, then, the perception of body as presenting statico-dynamical and statical attributes, is a state of consciousness having for its primary elements the impressions of resistance and extension unconditionally united with each other and the subject in relations of coincidence in time and adjacency in space; having for its secondary elements the impressions of touch, pressure, tension, and motion, variously united with one another in relations of simultaneity and sequence, that are severally conditional on the nature of the object and the acts of the subject, and all of them conditionally united with the primary elements by relations of sequence; and having for its further secondary elements certain yet undefined relations

(constituting the cognitions of size and form, hereafter to be analyzed), which are also conditionally united alike with the primary elements and the other secondary elements.

Such being the constituents of the perception, the act of perception consists in the classing these constituents, each with others of its own order. As shown in the last chapter, no one of them can be known for what it is, without being assimilated to the before-known ones which it resembles. And from the classing of each impression with like remembered impressions, each relation with like remembered relations, and each condition with like remembered conditions, results that classing of the object in its totality which is synonymous with a perception of it.

CHAPTER XIII.

THE PERCEPTION OF BODY AS PRESENTING STATICAL

ATTRIBUTES.

§ 326. From that class of attributes known to us solely through one or other kind of objective activity; and from that further class known to us through some objective reactivity called forth by a subjective activity; we now pass to that remaining class known to us through a subjective activity only.

In respect of its space-attributes-Bulk, Figure, and Position-body is altogether passive; and the perception of them is wholly due to certain mental operations. Unlike heat, sound, odour, &c., which are presented to consciousness by no acts of our own, but often in spite of our acts—unlike roughness, softness, pliability, &c., of which we become conscious by the union of our own acts with the acts of things; extension under its several modes is cognizable through a wholly-internal co-ordination of impressions: a process in which the extended object has no share. Though the data through which its extension is known, are supplied by the object; yet, as those data are not the extension, and as until they are combined in thought the extension is unknown, it follows that extension is an attribute with which body does not impress us, but which we discover through certain of its other attributes. To an uncritical observer, the visible form of an object seems as much thrust upon his

consciousness by the object itself, as its colour is. But on remembering that the visible form is revealed to him only through certain modifications of light; that these modifications are produced not by the form, but by certain occult properties of the substance having the form; and that if the body had no power of reacting on light, the form would be invisible; it will be seen that the form is known not immediately but mediately. When it is further remembered that in the dark the shape and size of anything are knowable only through tactual and muscular sensations gained by acts of exploration; and that consciousness of the shape and size depends on the thinking of these in certain relations; it will no longer be questioned that in the perception of the space-attributes, the object is wholly passive while the subject is active.

The propriety of distinguishing Bulk, Figure, and Position as statical attributes, may perhaps be questioned. In mechanics, statics and dynamics are allied to one another as closely as the circle is allied to the ellipse, into which it passes by insensible steps; whereas the attributes that are here classed as statical, differ wholly and irreconcilably from those classed as dynamical. The reply is that the terms as now used are to be understood, not in the mechanical sense, but in a more general sense. Statical attributes are those which pertain to body as standing or existing. Dynamical ones are those which pertain to it as acting. If it be admitted that the so-called secondary attributes of body, which, as we find, imply its activity, are rightly termed dynamical; it must be admitted that the so-called primary ones, which, as implying passivity, are their antitheses, may be properly distinguished as statical.

§ 327. Whether the space-attributes of body are any of them knowable through the eyes alone, has been a disputed question. That our perceptions of distance are not origi nally visual, but result from muscular experiences, which