it might be shown that the change from this first indefinite, incoherent and comparatively homogeneous consciousness, to a definite, coherent, and heterogeneous one, is due to differences in the actions of incident forces on the organism. These brief indications of what might be shown, did space permit, must here suffice. Probably they will give adequate clue to an argument by which each reader may satisfy himself that the course of mental evolution offers no exception to the general law. In further aid of such an argument, I will here add an illustration that is comprehensible apart from the process of mental evolution as a whole. It has been remarked (I am told by Coleridge, though I have been unable to find the passage) that with the advance of language, words which were originally alike in their meanings acquire unlike meanings—a change which he expresses by the formidable word “desynonymization.” Among indigenous words this loss of equivalence cannot be clearly shown; because in them the divergencies of meaning began before the dawn of literature. But among words that have been coined, or adopted from other languages, since the writing of books commenced, it is demonstrable. In the old divines, _miscreant_ is used in its etymological sense of _unbeliever_; but in modern speech it has entirely lost this sense. Similarly with _evil-doer_ and _malefactor_: exactly synonymous as these are by derivation, they are no longer synonymous by usage: by a _malefactor_ we now understand a convicted criminal, which is far from being the acceptation of _evil-doer_. The verb _produce_, bears in Euclid its primary meaning—to _prolong_, or _draw out_; but the now largely developed meanings of _produce_ have little in common with the meanings of _prolong_, or _draw out_. In the Church of England liturgy, an odd effect results from the occurrence of _prevent_ in its original sense—_to come before_, instead of its modern specialized sense—_to come before with the effect of arresting_. But the most conclusive cases are those in which the contrasted words consist of the same parts differently combined; as in _go under_ and _undergo_. We _go under_ a tree, and we _undergo_ a pain. But though, if analytically considered, the meanings of these expressions would be the same were the words transposed, habit has so far modified their meanings that we could not without absurdity speak of _undergoing_ a tree and _going under_ a pain. Countless such instances might be brought to show that between two words which are originally of like force, an equilibrium cannot be maintained. Unless they are daily used in exactly equal degrees, in exactly similar relations (against which there are infinite probabilities), there necessarily arises a habit of associating one rather than the other with particular acts, or objects. Such a habit, once commenced, becomes confirmed; and gradually their homogeneity of meaning disappears.