When expounded and applied to human affairs, Philosophy is not only a fine art in herself (_schöne Wissenschaft,_) but the mother of Beauty: it is only through her that Rhetoric and Poetry can ever be educational, useful, or in the truest sense pleasant."[67] [Sidenote: _Philosophy of language._] Herder and Hamann deserve our gratitude for having brought a current of fresh air into the study of the philosophy of language. The lead given by the Port-Royal authors had been followed since the beginning of the century by many writers of logical or general grammars. According to the French Encyclopædia, "_La grammaire générale est la science raisonnée des principes immuables et généraux de la parole prononcée ou écrite dans toutes les langues_,"[68] and d'Alembert spoke of grammarians of invention and grammarians of memory, assigning to the former the duty of studying the metaphysics of grammar.[69] General grammars had been written by Du Marsais, De Beauzée, and Condillac in France; Harris in England; and many others.[70] But what was the relation between general grammar and particular grammars? If logic be one, how comes it that languages are many? Is the variety of tongues but a deviation on their part from one single model? And, if there be no such deviation or error, what is the explanation of the fact? What is language, and how was it born? If language be external to thought, how can thought exist if not in language? "_Si les hommes_," says Jean-Jacques Rousseau, "_ont eu besoin de la parole pour apprendre à penser, ils ont eu bien plus besoin encore de savoir penser pour trouver l'art de la parole_"; appalled at the difficulty, he declares his conviction "_de l'impossibilité presque démontrée que les langues aient pu naître et s'établir par des moyens purement humains._"[71] Such questions became fashionable; books on the origin and formation of language were written by de Brosses (1765) and Court de Gébelin (1776) in France, by Monboddo (1774) in England, Süssmilch (1766) and Tiedemann in Germany, and Cesarotti (1785) in Italy, and by others who had some slight acquaintance with Vico, but profited little by it.[72] None of the above-named writers was able to free himself of the notion that speech was either natural and mechanical, or else a symbol attached to thought: whereas in fact it was impossible to solve the difficulties under which they were labouring except by dropping the notion of a sign or symbol and attaining the conception of the active and expressive imagination, verbal imagination, language as the expression not of intellect but of intuition. An approach towards this explanation was made by Herder in a brilliant and imaginative thesis in 1770 upon this subject of the origin of language, chosen for discussion by the Berlin Academy. In it he says that language is the reflexion or consciousness (_Besonnenheit_) of man. "Man shows reflexion when he puts forth freely such force of mind as enables him