immediate consciousness of a supreme and eternal unity is the primary standard by which we distinguish the just, the true, and the beautiful. Without this principle we should indeed be incapable of pursuing any general inquiry and of forming any judgement, so that demonstration and science can exist for those only who recognise a positive and supreme principle. We hold, therefore, that the true end of scientific inquiry (so far as it is to furnish explanation) is not to define and demonstrate the highest principle, but to trace other truths up to this, to show the harmony which, exists between nature and mind, or to discover a unity of law in the multiplicity of phænomena.
It is hoped that these general remarks may be sufficient to indicate the guiding principle of the following inquiries, which, being designed to lead to a clear conception of Life in general, and its single forms in particular, are here recommended by their author to the friendly attention and examination of medical men and naturalists, previously to their being, perhaps, at some future time, presented by himself or by some one else, in that strictly scientific form which is found so indispensably necessary to all who would penetrate the essence of nature, and obtain, instead of the vague and negative notions which commonly prevail, a distinct and positive knowledge.
If, with this view, we direct our attention to one only of the endless variety of forms which life assumes; if we observe, for instance, how a plant through internal instinct and under external relations unfolds itself from an obscure and insignificant seed, how its parts multiply, and how their organization becomes progressively more and more refined, until it reaches its acme in the flower, where the plastic power again concentrates itself into a seed, and thus closes the circle of its being in that form out of which it had first issued, we find throughout this chain of phænomena an internal pervading principle, a certain determinate succession, a regularity which compels us to expound all these movements, changes, and developments as parts of a whole, as the operations of one internal universal cause in which all others are comprehended. It is evident that this internal, this essential and efficient principle can be no single thing, such ,as the body of the plant, the chemical change of its substance, or the circulation of its sap, and still less the effect of external influences, but rather all these together—a something in which all these inhere as their common cause, and which we characterize as a unity by the generic appellation life. Hence it is easy to perceive how erroneous it would be, for instance, to suppose the plant first organized, and life then added to it as an attribute and consequently as something extrinsic, nearly in the same manner as we should conceive of a machine as a thing consisting of several parts put together and possessing, at first, no inherent power of acting, but having this power imparted to it when it is completed. On the contrary, life is necessarily the original principle, and the body one of its particular
