By going deeper into this twofold argument, we shall find, at its very root, the two fundamental illusions of the reflective consciousness. The first consists in regarding: intensity as a mathematical property of psychic states and not, as we said at the beginning of this essay, as a special quality, as a particular shade of these various states. The second consists in substituting for the concrete reality or dynamic progress, which consciousness perceives, the material symbol of this progress when it has already reached its end, that is to say, of the act already accomplished together with the series of its antecedents. Certainly, once the final act is completed, I can ascribe to all the antecedents their proper value, and picture the interplay of these various elements as a conflict or a composition of forces. But to ask whether, the antecedents being known as well as their value, one could foretell the final act, is to beg the question; it is to forget that we cannot know the value of the antecedents without knowing the final act, which is the very thing that is not yet known; it is to suppose wrongly that the symbolical diagram which we draw in our own way for representing the action _when completed_ has been drawn by the action itself _whilst progressing,_ and drawn by it in an automatic manner. [Sidenote: Claiming to foresee an action always comes back to confusing time with space.] Now, in these two illusions themselves a third one is involved, and you will see that the question whether the act could or could not be foreseen always comes back to this: Is time space? You begin by setting side by side in some ideal space the conscious states which succeed one another in Peter's mind, and you perceive his life as a kind of path M O X Y traced out by a moving body M in space. You then blot out in thought the part O X Y of this curve, and you inquire whether, knowing M O, you would have been able to determine the portion O X of the curve which the moving body describes beyond O. [Illustration]