After this, let us try to perceive change in itself, and then represent it to ourselves according to its specific and original nature. The common conception needs reform on two principal points: (1) All change is revealed in the light of immediate intuition, not as a numerical series of states, but a rhythm of phases, each of which constitutes an indivisible act, in such a way that each change has its natural inner articulations, forbidding us to break it up according to arbitrary laws, like a homogeneous length. (2) Change is self-sufficient; it has no need of a support, a moving body, a "thing" in motion. There is no vehicle, no substance, no spatial receptacle, resembling a theatre-scene, no material dummy successively draped in coloured stuffs; on the contrary, it is the body or the atom which should be subordinately defined as symbols of completed becoming. Of movement thus conceived, indivisible and substantial, what better image can we have than a musical evolution, a phrase in melody? That is how we must work to conceive reality. If such a conception at first appears obscure, let us credit experience, for ideas are gradually illuminated by the very use we make of them, "the clarity of a concept being hardly anything, at bottom, but the assurance once obtained that we can handle it profitably." (H. Bergson, "Introduction to Metaphysics".) If we require to reach a conception of this kind with regard to change, the Eleatic dialectic is there to establish it beyond dispute, and positive science comes to the same conclusion, since it shows us everywhere nothing but movements placed upon movements, never fixed "things," except as temporary symbols of what we leave at a given moment outside the field of study. In any case, the difficulty of such a conception need not stop us; it is little more than a difficulty of the imaginative order. And as for the conception itself, or rather the corresponding intuition, it will share the fate of all its predecessors: to our contemporaries it will be a scandal, a century later a stroke of genius, after some centuries common evidence, and finally an instinctive axiom. V. The Problem of Consciousness. Duration and Liberty. Armed with the method we have just described, Mr Bergson turned first of all toward the problem of the ego: taking up his position in the centre of mind, he has attempted to establish its independent reality by examining its profound nature. The first chapter of the "Essay on the Immediate Data" contains a decisive criticism of the conceptions which claim to introduce number and measure into the domain of the facts of consciousness.