In all cases that which, _abstractly_ taken, is the definition of the _kind_, will, when applied _absolutely_, or in its fullest sense, be the definition of the highest _degree_ of that kind. If life, in general, be defined _vis ab intra, cujus proprium est coadunare plura in rem unicam, quantùm est res unica_; the unity will be more intense in proportion as it constitutes each particular thing a whole of itself; and yet more, again, in proportion to the number and interdependence of the parts, which it unites as a whole. But a whole composed, _ab intra_, of different parts, so far interdependent that each is reciprocally means and end, is an individual, and the individuality is most intense where the greatest dependence of the parts on the whole is combined with the greatest dependence of the whole on its parts; the first (namely, the dependence of the parts on the whole) being absolute; the second (namely, the dependence of the whole on its parts) being proportional to the importance of the relation which the parts have to the whole, that is, as their action extends more or less beyond themselves. For this spirit of the whole is most expressed in that part which derives its importance as an End from its importance as a Mean, relatively to all the parts under the same copula.
Finally, of individuals, the living power will be most intense in that individual which, as a whole, has the greatest number of integral parts presupposed in it; when, moreover, these integral parts, together with a proportional increase of their interdependence, as _parts_, have themselves most the character of wholes in the sphere occupied by them. A mathematical point, line, or surface, is an _ens rationis_, for it expresses an intellectual act; but a physical atom is _ens fictitium_, which may be made subservient, as ciphers are in arithmetic, to the purposes of hypothetical construction, _per regulam falsi_; but transferred to _Nature_, it is in the strictest sense an _absurd_ quantity; for extension, and consequently divisibility, or _multeity_,(11) (for space cannot be divided,) is the indispensable condition, under which alone anything can _appear_ to us, or even be _thought_ of, as a _thing_. But if it should be replied, that the elementary particles are atoms not positively, but by such a hardness communicated to them as is relatively invincible, I should remind the assertor that _temeraria citatio supernaturalium est pulvinar intellectús pigri_, and that he who requires me to believe a miracle of his own dreaming, must first work a miracle to convince me that he had dreamt by inspiration. Add, too, the gross inconsistency of resorting to an immaterial influence in order to complete a system of materialism, by the exclusion of all modes of existence which the theorist cannot in imagination, at least, _finger_ and _peep_ at! Each of the preceding gradations, as above defined, might be represented as they exist, and are realised in Nature. But each would require a work for itself, co-extensive with the science of metals, and that of fossils (both as geologically applied); of crystallization; and of vegetable and animal physiology, in all its distinct branches. The nature of the present essay scarcely permits the space sufficient to illustrate our meaning. The proof of its probability (for to that only can we arrive by so partial an application of the hypothesis), is to be found in its powers of solving the particular class of phenomena, that form the subjects of the present inquisition, more satisfactorily and profitably than has been done, or even attempted before.