such a manner as to facilitate the observation of the marks of the object. For further illustration here are a few examples of the action of sense-perception in the third figure, by which two attributes are united by a causal idea: Tree, evergreen, resinous sap (resisting the action of cold). Bird, hooked beak, for tearing its prey. Bird, sharp talons, clutches living prey. Beast, chews cud, extra stomach. Beast, chews cud, divided hoofs (this contrast to the former is a mere subjective class, no causality being obvious). Beast, large pupil to eye, prowls at night. Desert plant, dew-absorbing, no rain. Summary.-The second figure classifies, using a property as its middle term. The first figure adds to the present observation the results of past observation, using the class as a middle term. The third figure, using the object as a middle term, perceives a new property and adds it to the class, making a new definition of a possible subclass, of which the object before it is an example.-There are three terms in sense-perceptionthe object, its class, its properties. The appropriate middle term is the object in the third figure, the class in the first figure, and a property in the second.-In Chapter V we have seen that a conception is not a mental picture, but a definition. Here we have found the process by which the definition arises.

§ 53. The ultimate consequences of this principle in psychology are important as touching the doctrine of categories of the mind. Sense-perception uses these categories unconsciously. Reflection subsequently discovers their existence, and finally their genesis. The fundamental act of mind, as self-determining, discriminates self from the special modification in which the self finds itself. The self is the general capacity for feeling, willing, knowing; but it

is at a given moment determined as one of these, if not exclusively, at least predominantly. Every act of perception begins with identification (second figure). This is an act of removal of the special limitation from the object—a dissolving of it in the general self as a capacity for any and all sensation, volition, or thought. Because to see an individual as a class is to neglect an infinite number of characteristics, and contemplate only the few belonging to the definition of this class. It is this first act that gives rise to the category of being, and the category of negation born with it is next perceived. All other categories arise from division of this most general of categories (summum genus). The third figure shows how these arise by progressive definition. The categories, in so far as they do not imply in their definition any properties derived from sense-perception, are called categories of pure thought or logic. Hegel undertakes to show the process of progressive definition by which these arise, in his logic (Wissenschaft der Logik).

CHAPTER XII.

The Body and the Mind.

854. In the last three chapters we have discussed the structure of the mind as revealed in its logical forms. The intellect has a logical constitution; it uses the syllogism in all its activity. It is a process of determining or of descent from the general to the particular, as in the third figure, or it is a process in the opposite direction, from the particular to the general, as in the second figure, which identifies particulars with general terms. In these investigations there can be no doubt that we have the real nature of the mind revealed to us. It is a self-activity whose forms of action are these three logical figures. In the present chapter we are to look at another method of studying the mind, that of the so-called physiological psychology. This method begins with the living organism and studies the correlation of mental phenomena with bodily changes. It seeks to find what phenomena of the soul correspond to various bodily stimuli. It is evident at the outset that there is some connection between the soul and the body; all human

experience presupposes this. We use the body in two ways: we perceive the external world by means of it, and we use the body as an instrument in order to produce changes on the world that we see. Here we have inward movement and outward movement through nerves-centripetal nerve-currents and centrifugal nerve-currents. Sensation is the sequence of the centripetal, and motor-impulse the antecedent of the centrifugal. The motor-impulse may proceed from the brain, or it may proceed from some ganglion of the spinal marrow. In both these currents we have what may be explained as mechanical action. It may be so explained, but it is not as yet so explained. Mechanical action borrows all its energy from another-it merely transmits it, and does not originate it. Vital action is self-activity in combination with mechanical action; it originates activity and guides it.) The process of digestion, common to animals and plants, is a vital activity. It takes possession of matter in its environment, and acts first destructively on its existing form, preparing it for food by fire, extinguishing its inherent vitality if it has any, and then subjecting it to processes of mastication and digestion, which deprive it of its other independent properties, and converting it into its own kind of animal cells. Here it acts constructively, giv

ing to the matter its own form and converting it into cellular tissue. In this process there is a struggle between the vital activity and the matter which it uses for food. The plant or animal, as vital, originates energy. Even if one claims that there is here a conservation of energy, and that the plant or animal derives or appropriates energy from its food, still it must be admitted that the plant or animal guides or directs this energy, and thus gives to it its psychical form. To guide or direct energy requires energy; it requires force to confine a force. Moreover, it is necessary that the guiding force be as strong as the force it guides. According to one view, the sequence of centripetal nerve-action, or the act of sensation, is self-active, and also the antecedent of the motoraction is a self-activity, while the two nerve-currents themselves are mechanical. But according to another view, both nerve-currents are vital and not mechanical. But the self-activity ends somewhere and the mechanical begins, it may be in one place or in another. The action produced by the muscles and the bones is certainly mechanical. The origination of motion before the nerves receive it is certainly selfactivity. The spiritual individuality of the soul builds its body and uses it in interaction with the world, in perception and in volition.