In the higher grades of the objectivity of will we see individuality occupy a prominent position, especially in the case of man, where it appears as the great difference of individual characters, i.e., as complete personality, outwardly expressed in strongly marked individual physiognomy, which influences the whole bodily form. None of the brutes have this individuality in anything like so high a degree, though the higher species of them have a trace of it; but the character of the species completely predominates over it, and therefore they have little individual physiognomy. The farther down we go, the more completely is every trace of the individual character lost in the common character of the species, and the physiognomy of the species alone remains. We know the physiological character of the species, and from that we know exactly what is to be expected from the individual; while, on the contrary, in the human species every individual has to be studied and fathomed for himself, which, if we wish to forecast his action with some degree of certainty, is, on account of the possibility of concealment that first appears with reason, a matter of the greatest difficulty. It is probably connected with this difference of the human species from all others, that the folds and convolutions of the brain, which are entirely wanting in birds, and very weakly marked in rodents, are even in the case of the higher animals far more symmetrical on both sides, and more constantly the same in each individual, than in the case of human beings.34 It is further to be regarded as a phenomenon of this peculiar individual character which distinguishes men from all the lower animals, that in the case of the brutes the sexual instinct seeks its satisfaction without observable choice of objects, while in the case of man this choice is, in a purely instinctive manner and independent of all reflection, carried so far that it rises into a powerful passion. While then every man is to be regarded as a specially determined and characterised phenomenon of will, and indeed to a certain extent as a special Idea, in the case of the brutes this individual character as a whole is wanting, because only the species has a special significance. And the farther we go from man, the fainter becomes the trace of this individual character, so that plants have no individual qualities left, except such as may be fully explained from the favourable or unfavourable external influences of soil, climate, and other accidents. Finally, in the inorganic kingdom of nature all individuality disappears. The crystal alone is to be regarded as to a certain extent individual. It is a unity of the tendency in definite directions, fixed by crystallisation, which makes the trace of this tendency permanent. It is at the same time a cumulative repetition of its primitive form, bound into unity by an idea, just as the tree is an aggregate of the single germinating fibre which shows itself in every rib of the leaves, in every leaf, in every branch; which repeats itself, and to some extent makes each of these appear as a separate growth, nourishing itself from the greater as a parasite, so that the tree, resembling the crystal, is a systematic aggregate of small plants, although only the whole is the complete expression of an individual Idea, i.e., of this particular grade of the objectification of will. But the individuals of the same species of crystal can have no other difference than such as is produced by external accidents; indeed we can make at pleasure large or small crystals of every species. The individual, however, as such, that is, with traces of an individual character, does not exist further in unorganised nature. All its phenomena are expressions of general forces of nature, i.e., of those grades of the objectification of will which do not objectify themselves (as is the case in organised nature), by means of the difference of the individualities which collectively express the whole of the Idea, but show themselves only in the species, and as a whole, without any variation in each particular example of it. Time, space, multiplicity, and existence conditioned by causes, do not belong to the will or to the Idea (the grade of the objectification of will), but only to their particular phenomena. Therefore such a force of nature as, for example, gravity or electricity, must show itself as such in precisely the same way in all its million phenomena, and only external circumstances can modify these. This unity of its being in all its phenomena, this unchangeable constancy of the appearance of these, whenever, under the guidance of causality, the necessary conditions are present, is called a law of nature. If such a law is once learned from experience, then the phenomenon of that force of nature, the character of which is expressed and laid down in it, may be accurately forecast and counted upon. But it is just this conformity to law of the phenomena of the lower grades of the objectification of will which gives them such a different aspect from the phenomena of the same will in the higher, i.e., the more distinct, grades of its objectification, in animals, and in men and their actions, where the stronger or weaker influence of the individual character and the susceptibility to motives which often remain hidden from the spectator, because they lie in knowledge, has had the result that the identity of the inner nature of the two kinds of phenomena has hitherto been entirely overlooked.
If we start from the knowledge of the particular, and not from that of the Idea, there is something astonishing, and sometimes even terrible, in the absolute uniformity of the laws of nature. It might astonish us that nature never once forgets her laws; that if, for example, it has once been according to a law of nature that where certain materials are brought together under given conditions, a chemical combination will take place, or gas will be evolved, or they will go on fire; if these conditions are fulfilled, whether by our interposition or entirely by chance (and in this case the accuracy is the more astonishing because unexpected), to-day just as well as a thousand years ago, the determined phenomenon will take place at once and without delay. We are most vividly impressed with the marvellousness of this fact in the case of rare phenomena, which only occur under very complex circumstances, but which we are previously informed will take place if these conditions are fulfilled. For example, when we are told that if certain metals, when arranged alternately in fluid with which an acid has been mixed, are brought into contact, silver leaf brought between the extremities of this combination will suddenly be consumed in a green flame; or that under certain conditions the hard diamond turns into carbonic acid. It is the ghostly omnipresence of natural forces that astonishes us in such cases, and we remark here what in the case of phenomena which happen daily no longer strikes us, how the connection between cause and effect is really as mysterious as that which is imagined between a magic formula and a spirit that must appear when invoked by it. On the other hand, if we have attained to the philosophical knowledge that a force of nature is a definite grade of the objectification of will, that is to say, a definite grade of that which we recognise as our own inmost nature, and that this will, in itself, and distinguished from its phenomena and their forms, lies outside time and space, and that, therefore, the multiplicity, which is conditioned by time and space, does not belong to it, nor directly to the grade of its objectification, i.e., the Idea, but only to the phenomena of the Idea; and if we remember that the law of causality has significance only in relation to time and space, inasmuch as it determines the position of the multitude of phenomena of the different Ideas in which the will reveals itself, governing the order in which they must appear; if, I say, in this knowledge the inner meaning of the great doctrine of Kant has been fully grasped, the doctrine that time, space, and causality do not belong to the thing-in-itself, but merely to the phenomenon, that they are only the forms of our knowledge, not qualities of things in themselves; then