Our intellectual machine sometimes works in accord with the external law and at others makes mistakes and goes the wrong way. Then we are obliged to correct it, and to try a better adjustment, either by profounder experimenting with nature (methods of concordance, discordance, variations, &c.), or by a comparison of different judgments and arguments made into a synthesis; and this collaboration of several concordant activities ends in a conclusion which can never represent the truth, but only the probable truth. The study of the laws of the mind shows us too clearly, in fact, their fluidity with regard to the laws of nature for us not to accept probabilism. There exists no certitude—only very varied degrees of probability. Daily practice contents itself with a very low degree of probability; judicial logic demands a rather higher one, especially when it is a question of depriving one of our fellow-creatures of liberty or life. Science claims one higher still. But there is never anything but differences of degrees in probability and conjecture.
This, then, is the definition of psychology that we propose. It studies a certain number of laws which we term mental, in opposition to those of external nature, from which they differ, but which, properly speaking, do not deserve the qualification of mental, since they are—or at least the best known of them are—laws of the images, and the images are material elements. Although it may seem absolutely paradoxical, psychology is a science of matter—the science of a part of matter which has the property of preadaptation.
FOOTNOTES:
[33] Lange, Histoire du Matérialisme, II., 2me. partie, chap. iii.
[34] Let us remark, in passing, how badly nature has organised the system of communication between thinking beings. In what we experience we have nothing in common with our fellows; each one experiences his own sensations and not those of others. The only meeting point of different minds is found in the inaccessible domain of the noumena.
[35] E. Rabier, Leçons de Philosophie, "Psychologie," p. 33.
[36] This seems to have been the opinion of Democritus. The modern doctrine of radiation from the human body, if established, would go nearly as far as the supposition in the text. Up till now, however, it lacks confirmation.—Ed.
[37] I am compelled, much against my will, to use throughout this passage an equivocal expression, that of "mental law," or law of consciousness, or psychological law. I indicate by this the laws of contiguity and of similarity; as they result from the properties of the images, and as these are of a material nature, they are really physical and material laws like those of external nature. But how can all these laws be called physical laws without running the risk of confusing them one with the other?
[38] Finality seems to be here used in the sense of the doctrine which regards perfection as the final cause of existence.—Ed.
[39] See a very interesting article by E. Goblot, "La Finalité sans Intelligence," Revue de Métaphysique, July 1900.