Among the latter, the principal is the law of analogy, the great artisan in the extension of languages. It is a law of economy, the basis of which is generalisation, the faculty of seizing on real or supposed resemblances. The word remains invariable, but the mind gives it different applications: it is a mask covering in turn several faces. It suffices to open a dictionary to see how ingenious and perilous is this unconscious labor. Such a word has only a few lines; it has no brilliant record. Such another fills pages; first we see it in its primitive sense; then—from analogy to analogy—from accident to accident—it departs from it more and more, and ends by having quite a contrary meaning.[66] Hence it has been said that “the object of a true etymology is to discover the laws that have regulated the evolution of thought.” Among primitive people, the process that entails such deviations from the primitive sense, is sometimes of striking absurdity; or at least appears to us as such by reason of the strange analogies that serve the extension of the word. Thus: certain Australian tribes gave the names of mussels (muyum), to books because they open and close like shell-fish; and many other no less singular facts could be cited. Much more might be said as to the rôle of analogy, but we must adhere to our subject.
In conclusion: it is to be regretted that linguistic psychology attracts so few people, and that many recent treatises on psychology, excellent on all other points, do not devote a single line to language. Yet this study, especially if comparative, from the lowest to the most subtle forms, would throw at least as much light on the mechanism of the intelligence as other highly accredited processes. Physiological psychology is much in vogue, since it is rightly concluded that if the facts of biology, normal and morbid, are being studied by naturalists and physicians, they are available to psychologists also, under another aspect. So too for languages: comparative philology has its own aim, psychology another, proper to it. It is incredible that any one who, with sufficient linguistic equipment, should devote himself to the task, would fail to find adequate return for his labors.
CHAPTER III.
INTERMEDIATE FORMS OF ABSTRACTION.
Having thus acquainted ourselves with this new factor—speech—which as an instrument of abstraction becomes steadily more and more important, we can take up our subject from the point at which we left it. In passing from the absence to the presence of the word, from the lower to the intermediate forms of abstraction, we must again insist on our principal aim: viz., to prove that abstraction and generalisation are functions of the completely evolved mind. They exist in embryo in perception, and in the image, and at their extreme limit involve suppression of all concrete representation. This conclusion will hardly be contradicted. The difficulty is to follow the evolution step by step, stage after stage, and to note the difference by objective marks.
For intermediate abstraction, this operation is very simple. It implies the use of words; it has passed the level of pre-linguistic abstraction and generalisation. We may go farther, and—always with the aid of words—establish two classes within the total category of mean abstraction:
1. The lower forms, bordering on generic images, whose objective mark is the feeble participation of the word: it can indeed be altogether foregone, and is only in the least degree an instrument of substitution.
2. The higher forms, approximating to the class of pure concepts, and having as their objective mark the fact that words are indispensable, since these have now become an instrument of substitution, though still accompanied by some sensory representation.
The legitimacy of this division can be justified only by a detailed comparison of the two classes.