Prof. Max Müller says (The Monist, p. 585):
"If, like Professor Romanes, we begin with the 'immense presumption that there has been no interruption in the developmental process in the course of psychological history,' the protest of language counts for nothing; the very fact that no animal has ever formed a language, is put aside simply as an unfortunate accident."
The theory of evolution rightly understood is no presumption in the usual sense of the word. It is no more a presumption than to say that something cannot come from nothing. And what is "the protest of language" which would disprove the continuity of evolution? That rational or human thought is something sui generis, that it is different in kind and not in degree from brute intelligence; that language is an impassable barrier between man and brute, being the Rubicon which no other animal has crossed. Very well. We agree entirely with all these propositions. Human reason is different in kind from brute intelligence and human reason has developed such as it is through language only. Nay reason is language. Noiré is right when he says, Man thinks because he speaks. But the Rubicon of language was not an absolutely impassable barrier. The speechless ancestor of man, whether we call him homo alalus or an thropoid, or even man-ape, has crossed it, and having crossed it he became the Cæsar of the animal creation.
Prof. Max Müller's theory of the identity of language and thought[1] is so valuable because it bridges the gap between the rational sphere of man and the not-yet rational sphere of the brute creation. It explains the origin of reason. The origin of reason in the world of living beings is explained as soon as the origin of language is understood, for reason develops with language and rational thought is nothing but rational speech. If the origin of language were an unfathomable mystery, Prof. Max Müller's view of the identity of language and thought would lose all practical importance.
The proposition of the identity of language and thought is a very radical idea; it is the fundamental idea of monism. In a more general form it was first pronounced by Giordano Bruno, who says
- ↑ I should prefer to speak of the oneness or inseparableness of thought and language, but since Prof. Max Muller has sufficiently explained himself, I use here his term "identity" in the sense of inseparableness as it is used by Prof. Max Müller.
