Over these definitions by point of view, one might quibble a little; for those who thus define psychology are not always consistent with themselves. In other passages of their writings they do not fail to oppose psychical to physiological phenomena, and they proclaim the irreducible heterogeneity of these two orders of phenomena and the impossibility of seeing in physics the producing cause of the moral. Ebbinghaus is certainly one of the modern writers who have most strongly insisted on this idea of opposition between the physiological and the psychical, and he is a convinced dualist. Now I do not very clearly understand in what the principle of heterogeneity can consist to a mind which admits, on the other hand, that psychology does not differ from the physical sciences by its content.
However, I confine myself here to criticising the consequences and not the starting point. The definition of the psychical phenomenon by the point of view seems to me correct, although it has more concision than clearness; for it rests especially upon a material metaphor, and the expression "point of view" hardly applies except to the changes of perspective furnished by visible objects.
It would be more exact to say that psychology specially studies certain objects of cognition, such as those which have the character of representations (reminiscences, ideas, concepts), the emotions, the volitions, and the reciprocal influences of these objects among themselves. It studies, then, a part of the material world, of that world which till now has been called psychological, because it does not come under the senses, and because it is subjective and inaccessible to others than ourselves; it studies the laws of those objects, which laws have been termed mental.[37]
These laws are not recognised, popularly speaking, either in physics or in biology; they constitute for us a cognition apart from that of the natural world. Association by resemblance, for example, is a law of consciousness; it is a psychological law which has no application nor counterpart in the world of physics or biology. We may therefore sum up what has been said by the statement that psychology is the study of a certain number of laws, relations, and connections.
As to the particular feature which distinguishes mental from physical laws, we can formulate it, as does William James, by saying that the essence of a mental law is to be teleological, or, if the phrase be preferred, we can say that mental activity is a finalistic activity, which expends itself as will in the pursuit of future ends, and as intelligence in the choice of the means deemed capable of serving those ends. An act of intelligence is recognised by the fact of its aiming at an end, and employing for this end one means chosen out of many. Finality and intelligence are thus synonymous. In opposition to mental law, physical law is mechanical, by which expression is simply implied the absence of finality. Finality opposed to mechanism; such is the most concise and truest expression in which must be sought the distinctive attribute of psychology and of the moral sciences, the essential characteristic by which psychological are separated from physical facts.
I think it may be useful to dwell a little on the mental laws which I have just opposed to the physical, and whose object is to assure preadaptation and form a finality.[38] Their importance cannot be exaggerated. Thanks to his power of preadaptation, the being endowed with intelligence acquires an enormous advantage over everything which does not reason. No doubt, as has been shrewdly remarked, natural selection resembles a finality, for it ends in an adaptation of beings to their surroundings. There is therefore, strictly speaking, such a thing as finality without intelligence. But the adaptation resulting therefrom is a crude one, and proceeds by the elimination of all that does not succeed in adapting itself; it is a butchery. Real finalism saves many deaths, many sufferings, and many abortions.[39]
Let us examine, then, the process of preadaptation; it will enable us to thoroughly comprehend, not only the difference between the physical and the psychical laws, but the reason why the psychical manages in some fashion to mould itself upon the physical law.
Now, the means employed by preadaptation is, if we take the matter in its simplest form, to be aware of sensations before they are experienced. If we reflect that all prevision implies a previous knowledge of the probable trend of events, it will be understood that the part played by intelligence consists in becoming imbued with the laws of nature, for the purpose of imitating its workings. By the laws of nature, we understand here only that order of real sensations, the knowledge of which is sufficient to fulfil the wants of practical life. To us there are always gaps in this order, because the sensation it is important for us to know is separated from us either by the barriers of time or of space, or by the complication of useless sensations. Thence the necessity of interpolations. That which we do not perceive directly by our senses, we are obliged to represent to ourselves by our intelligence; the image does the work of sensation, and supplements the halting sensation in everything which concerns adaptation.
To replace the inaccessible sensation by the corresponding image, is therefore to create in ourselves a representation of the outer world which is, on all the points most useful to us, more complete than the direct and sensorial presentation of the moment. There is in us a power of creation, and this power exercises itself in the imitation of the work of nature; it imitates its order, it reconstitutes on the small scale adapted to our minds, the great external order of events. Now, this work of imitation is only really possible if the imitator has some means at his disposal analogous to those of the model.
Our minds could not divine the designs of nature, if the laws of images had nothing in common with the laws of nature. We are thus led to confront these two orders of laws with each other; but, before doing so, one more preliminary word is necessary. We have up till now somewhat limited the problem, in order to understand it. We have reduced the psychological being to one single function, the intellectual, and to one single object of research, the truth. This is, however, an error which has often been committed, which is now known and catalogued, called intellectualism, or the abuse of intellectualism. It is committed for this very simple reason, that it is the intellectual part of our being which best allows itself to be understood, and, so to speak, intellectualised. But this leaves out of the question a part of our entire mental being so important and so eminent, that if this part be suppressed, the intelligence would cease to work and would have no more utility than a machine without motive power. Our own motive power is the will, the feeling, or the tendency. Will is perhaps the most characteristic psychical function, since, as I have already had occasion to say, nothing analogous to it is met with in the world of nature. Let us therefore not separate the will from the intelligence, let us incarnate them one in the other; and, instead of representing the function of the mind as having for its aim knowledge, foresight, the combination of means, and self-adaptation, we shall be much nearer the truth in representing to ourselves a being who wills to know, wills to foresee, and wills to adapt himself, for, after all, he wills to live.