We shall presently see that this distinction between the naming and the predicating phases of language is of the highest importance in relation to the subject of the present treatise; but meanwhile all we have to note is that the naming phase of spoken language occurs—in a rudimentary form, indeed, but still unquestionably—in the animal kingdom; and that the fact of its doing so is not surprising, if we remember that in this stage language is nothing more than vocal gesticulation. Psychologically considered, there is nothing more remarkable in the fact that a bird which is able to utter an articulate sound should learn by association to use that sound as a conventional sign, than there is that it should learn by association similarly to use a muscular action, as it does in the act of depressing its head as a sign to have it scratched. Therefore we may now, I think, take the position as established _a posteriori_ as well as _a priori_, that it is, so to speak, a mere accident of anatomy that all the higher animals are not able thus far to talk; and that, if dogs or monkeys were able to do so, we have no reason to doubt that their use of words and phrases would be even more extensive and striking than that which occurs in birds. Or as Professor Huxley observes, “a race of dumb men, deprived of all communication with those who could speak, would be little indeed removed from the brutes. The moral and intellectual differences between them and ourselves would be practically infinite, though the naturalist should not be able to find a single shadow even of specific structural difference.[87]