Less even than that: for very soon, by increasing abstraction, the coloured views give place to regular lines, and even to simple conventional notes, which are more practical in use and waste less time. And so the sciences remain prisoners of the symbol, and all the inevitable relativity involved in its use. But philosophy claims to pierce within reality, establish itself in the object, follow its thousand turns and folds, obtain from it a direct and immediate feeling, and penetrate right into the concrete depths of its heart; it is not content with an analysis, but demands an intuition. Now there is one existence which, at the outset, we know better and more surely than any other; there is a privileged case in which the effort of sympathetic revelation is natural and almost easy to us; there is one reality at least which we grasp from within, which we perceive in its deep and internal content. This reality is ourselves. It is typical of all reality, and our study may fitly begin here. Psychology puts us in direct contact with it, and metaphysics attempt to generalise this contact. But such a generalisation can only be attempted if, to begin with, we are familiar with reality at the point where we have immediate access to it. The path of thought which the philosopher must take is from the inner to the outer being. I. "Know thyself": the old maxim has remained the motto of philosophy since Socrates, the motto at least which marks its initial moment, when, inclining towards the depth of the subject, it commences its true work of penetration, whilst science continues to extend on the surface. Each philosophy in turn has commented upon and applied this old motto. But Mr Bergson, more than anyone else, has given it, as he does everything else he takes up, a new and profound meaning. What was the current interpretation before him? Speaking only of the last century, we may say that, under the influence of Kant, criticism had till now been principally engaged in unravelling the contribution of the subject in the act of consciousness, in establishing our perception of things through certain representative forms borrowed from our own constitution. Such was, even yesterday, the authenticated way of regarding the problem. And it is precisely this attitude which Mr Bergson, by a volte-face which will remain familiar to him in the course of his researches, reverses from the outset.