propositions only in that they do not themselves become objects of thought. And the only difference between such a statement when made by a young child, and the same statement when similarly made by a grown man, is that in the former case it is not even _potentially_ capable of itself becoming an object of thought. * * * * * Here, then, the psychological examination of my opponents’ position comes to an end. And, in the result, I claim to have shown that in whatever way we regard the distinctively human faculty of conceptual predication, it is proved to be but a higher development of that faculty of receptual communication, the ascending degrees of which admit of being traced through the brute creation up to the level which they attain in a child during the first part of its second year,—after which they continue to advance uninterruptedly through the still higher receptual life of the child, until by further though not less imperceptible growth they pass into the incipiently conceptual life of a human mind—which, nevertheless, is not even then nearly so far removed from the intelligence of the lower animals, as it is from that which in the course of its own subsequent evolution it is eventually destined to become. CHAPTER XII. COMPARATIVE PHILOLOGY. We have now repeatedly seen that there is only one argument in favour of the view that the elsewhere continuous and universal process of evolution—mental as well as organic—was interrupted at its terminal phase, and that this argument stands on the ground of psychology. But we have also seen that even upon this its own ground the argument admits of abundant refutation. In order the more clearly to show that such is the case, I have hitherto designedly kept my discussion within the limits of psychological science. The time, however, has now come when I can afford to take a new point of departure. It is to Language that my opponents appeal: to Language they shall go. In previous chapters I have more than once remarked that the science of historical psychology is destitute of fossils: unlike pre-historic structures, pre-historic ideas leave behind them no record of their existence. But now a partial exception must be taken to this general statement. For the new science of Comparative Philology has revealed the important fact that, if on the one hand speech gives _ex_pression _to_ ideas, on the other hand it receives _im_pression _from_ them, and that the impressions thus stamped are surprisingly persistent. The consequence is that in philology we possess the same kind of unconscious record of the growth and decay of ideas, as is furnished by palæontology of the growth and decay of species. Thus viewed, language may be regarded as the stratified deposit of thoughts, wherein they lie embedded ready to be unearthed by the labours of the man of science.