224 DR. CARUS ON THE KINGDOMS OF NATURE, 
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 phenomena. 
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 atten- 
tion 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 indispen- 
sably 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 end- 
less variety of forms which life assumes ; if we observe, for instance, 
how a plant through internal instinct and under external relations un- 
folds itself from an obscure and insignificant seed, how its parts mul- 
tiply, 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 phenomena an internal pervading principle, a certain de- 
terminate succession, a regularity which compels us to expound all these 
movements, changes, and developments as parts of a whole, as the ope- 
rations of one internal universal cause in which all others are compre- 
hended. 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 am attribute and con- 
sequently 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 
