Before, however, finally dismissing the _Essay_, I must pause to ask what was the main work in the history of philosophy and thought which it accomplished. Many of its individual doctrines, doubtless, could not now be defended against the attacks of hostile criticism, and some even of those which are true in the main, are inadequate or one-sided. But its excellence lies in its tone, its language, its method, its general drift, its multiplicity of topics, the direction which it gave to the thoughts and studies of reflecting men for many generations subsequent to its appearance. Of the tone of candour and open-mindedness which pervades it, of the unscholastic and agreeable form in which it is written, and of the great variety of interesting topics which it starts, I have spoken already. Its method, though not absolutely new, even in modern times, for it is at least, to some extent, the method of Descartes, if not, in a smaller degree, of Hobbes and Gassendi, was still not common at the time of its appearance. Instead of stating a series of preconceived opinions, or of dogmas borrowed from some dominant school, in a systematic form, Locke sets to work to examine the structure of his own mind, and to analyze into their elements the ideas which he finds there. This, the _introspective_ method, as it has been called, though undoubtedly imperfect, for it requires to be supplemented by the study of the minds of other men, if not of the lower animals, as made known by their acts, and words, and history, is yet a great advance on the purely _à priori_, and often fanciful, methods which preceded it. Nor do we fail to find in the _Essay_ some employment of that _comparative_ method to which I have just alluded: witness the constant references to children and savages in the first book, and the stress which is laid on the variety of moral sentiment existing amongst mankind. This inductive treatment of philosophical problems, mainly introspective, but in some measure also comparative, which was extremely rare in Locke's time, became almost universal afterwards. Closely connected with the method of the book is its general purport. By turning the mind inwards upon itself, and "making it its own object," Locke surmises that all its ideas come either from without or from experience of its own operations. He finds, on examination and analysis, no ideas which cannot be referred to one or other of these two sources. The single word "experience" includes them both, and furnishes us with a good expression for marking the general drift of his philosophy. It was pre-eminently a philosophy of experience, both in its method and in its results. It accepts nothing on authority, no foregone conclusions, no data from other sciences. It digs, as it were, into the mind, detaches the ore, analyzes it, and asks how the various constituents came there. The analytical and psychological direction thus given to philosophy by Locke was followed