animated, that the distinction which has been made between animate and inanimate bodies does not exist. When a stone is thrown into the air, and falls to earth according to definite laws, or when in a solution of salt a crystal is formed, the phenomenon is neither more nor less a mechanical manifestation of life than the growth and flowering of plants, than the propagation of animals or the activity of their senses, than the perception or the formation of thought in man." Here crystallization, organic life, sensation, and formation of thought, are expressly put in one line of mechanism with the falling of a stone.
In the following section we will have occasion to discuss this view as a view of the world; but we believe that the presentation of this idea, and the exclusive vindication of it as a complete view of the world, needs just here, where we still stand on the ground of the philosophy of natural perception, some critical sifting.
In the realm of material nature, mechanical explanation and general explanation is directly identical; i.e., a process of nature remains obscure so long and so far as its mechanism is not yet perceived, and in the same degree as its mechanism is perceived, the process also is explained. The uniformity of law in the occurrence of events according to the causal principle in the realm of material nature, can be approached by us in no other form than in that of mechanism, provided we understand by mechanism an activity according to law and which can be mathematically estimated as to size and number. So far, therefore, every scientific investigator in the knowledge of material nature takes his place on the standpoint of a mechanical view of the world.
But here we have gone to the full extent to which we are justified in taking a mechanical view of the world, and have fixed its limits in its own proper realm—the realm of the scientific perception of the material world; even if we do not join with Wigand in resigning scientific inquiry in that direction, and express the expectation that these limits are not fixed and not to be designated in advance, but will be moved farther and farther, and that not only in regard to the knowledge of the quantity of phenomena (which even Wigand, as a scientific investigator, naturally admits), but also in regard to their quality. In our researches hitherto we have often met such limits. We have found that in the realm of the material world such important phenomena and processes as life are at present not yet fully explained. By the mechanical view of the world, we have been led back to the last elements and to the most elementary forces of matter, but have been convinced that we are no longer able to find them with scientific certainty, and that consequently not a single quality of material existence is really explained and traced back to its last material causes, to say nothing of the transcendental causes which are entirely inaccessible to our exact scientific knowledge.
Now there is another realm of existence, just as large as and, according to its value, still larger than, that of the material world, which, not on account of its scientific inaccessibility, but in conformity with its own peculiar nature, entirely withdraws itself from the mechanical view. It is the realm of psychical life; and, still more decidedly and more evidently, the realm of mind. As far as our observations go, the law of
causality reigns here also, and here also nothing takes place without a cause. But as here the realm in which the causal law reigns is no longer material nature, so even the form in which it is active is no longer that of mechanism. For we certainly cannot understand mechanical effect to be anything else than an effect of something material upon something material, whose uniformity of law can be exactly estimated mathematically as to size and number. Now if the application of mechanism to the psychical and spiritual realm does not express anything except the certainly quite insidious idea that here also causality reigns, it is nothing else but the substitution of another idea for the word mechanism—an idea which it never had in the entire use of language up to this time, and by the substitution of which the proof for a mechanism of the mind is not given, but surreptitiously obtained in a manner similar to the before-mentioned attempt of Preyer, surreptitiously to obtain the proof for the origin of life.
But if the mechanical explanation of the functions of the mind really means that they also consist in an effect of the material upon something material, and that this effect can be mathematically estimated as to size and number, it is an assertion which has first to be proven, but which cannot be proven and cannot be allowed even as an hypothesis, as a problem for investigation, because it contradicts our whole experience. And it contradicts not only the conclusions drawn from most natural appearances, which, as is well known, are deceitful and even tell us that the sun goes around the earth, but it contradicts the philosophical analysis just as much and even still more directly and decidedly than
the direct impression—as became clear to us at the lowest point of contact between the material and the psychical, viz., at sensation, when we showed the impossibility of scientifically explaining the origin of sensation.
It is easy to see what facts made it altogether possible to produce such a materialistic psychology and to give it at the first superficial view a certain appearance of truth; but it will not be difficult to detect its want of truth. According to our whole experience, the human mind is bound to the body; its proper activity, its whole communication with the material and immaterial world outside of it, even its whole mutual intercourse with the minds of fellow-beings, is performed by means of bodily functions which, as such, are subordinate to mechanism. Therefore "physiological psychology" certainly belongs to the most interesting of the branches of science which at present enjoy special care, and works in this realm, like those of Wundt, are worthy of the greatest attention. Now if these points of contact once exist between the material and the psychical and spiritual processes, so that material functions causally influence psychical and spiritual ones, and psychical and spiritual functions similarly influence material ones, there must also exist between the laws of material processes and those of psychical and spiritual functions a relation which makes possible such a mutual effect, and we must be able to abstract from it the existence of a common higher law of which on the one side the material laws, and on the other the psychical and spiritual, are but partial laws. Precisely here lie the indications which appear to favor materialism in psychology. But it is only an appearance. For, from the acknowledgment