In the first step, we had Life, as the mere _unity_ of powers; in the second we have the simplest forms of _totality_ evolved. The third step is presented to us in those vast formations, the tracing of which generically would form the science of Geology, or its history in the strict sense of the word, even as their description and diagnostics constitute its preliminaries.
Their claim to this rank I cannot here even attempt to support. It will be sufficient to explain my reason for having assigned it to them, by the avowal, that I regard them in a twofold point of view: 1st, as the residue and product of vegetable and animal life; 2d, as manifesting the tendencies of the Life of Nature to vegetation or animalization. And this process I believe--in one instance by the peat morasses of the northern, and in the other instance by the coral banks of the southern hemisphere--to be still connected with the present order of vegetable and animal Life, which constitute the fourth and last step in these wide and comprehensive divisions.
In the lowest forms of the vegetable and animal world we perceive totality dawning into _individuation_, while in man, as the highest of the class, the individuality is not only perfected in its corporeal sense, but begins a new series beyond the appropriate limits of physiology. The tendency to individuation, more or less obscure, more or less obvious, constitutes the common character of all classes, as far as they maintain for themselves a distinction from the universal life of the planet; while the degrees, both of intensity and extension, to which this tendency is realized, form the species, and their ranks in the great scale of ascent and expansion.
In the treatment of a subject so vast and complex, within the limits prescribed for an essay like the present, where it is impossible not to say either too much or too little (and too much because too little), an author is entitled to make large claims on the candour of his judges. Many things he must express inaccurately, not from ignorance or oversight, but because the more precise expression would have involved the necessity of a further explanation, and this another, even to the first elements of the science. This is an inconvenience which presses on the analytic method, on however large a scale it may be conducted, compared with the synthetic; and it must bear with a tenfold weight in the present instance, where we are not permitted to avail ourselves of its usual advantages as a counterbalance to its inherent defects. I shall have done all that I dared propose to myself, or that can be justly demanded of me by others, if I have succeeded in conveying a sufficiently clear, though indistinct and inadequate notion, so as of its many results to render intelligible that one which I am to apply to my particular subject, not as a truth already demonstrated, but as an hypothesis, which pretends to no higher merit than that of explaining the particular class of phenomena to which it is applied, and asks no other reward than a presumption in favour of the general system of which it affirms itself to be a dependent though integral part. By Life I everywhere mean the true Idea of Life, or that most general form under which Life manifests itself to us, which includes all its other forms. This I have stated to be the _tendency to individuation_, and the degrees or intensities of Life to consist in the progressive realization of this tendency. The power which is acknowledged to exist, wherever the realization is found, must subsist wherever the tendency is manifested. The power which comes forth and stirs abroad in the bird, must be latent in the egg. I have shown, moreover, that this tendency to individuate cannot be conceived without the opposite tendency to connect, even as the centrifugal power supposes the centripetal, or as the two opposite poles constitute each other, and are the constituent acts of one and the same power in the magnet. We might say that the life of the magnet subsists in their union, but that it lives (acts or manifests itself) in their strife. Again, if the tendency be at once to individuate and to connect, to detach, but so as either to retain or to reproduce attachment, the individuation itself must be a tendency to the ultimate production of the highest and most comprehensive individuality. This must be the one great end of Nature, her ultimate object, or by whatever other word we may designate that something which bears to a final cause the same relation that Nature herself bears to the Supreme Intelligence.