certitude as the perception of the moment. Certain witnesses would write their depositions with their blood. One does not see this every day; but still one does see it.
Further, there are thousands of circumstances where the ideation is neither in conflict with the perception nor isolated from it, but in logical continuity with it. This continuity must even be considered as the normal condition. We think in the direction of that which we perceive. The image seems to prepare the adaptation of the individual to his surroundings; it creates the foresight, the preparation of the means, and, in a word, everything which constitutes for us a final cause. Now, it is very necessary that the image appear real to be usefully the substitute of the sensation past or to come.
Let us establish one thing more. Acting as a substitute, the image not only appears as real as the sensation, it appears to be of the same nature; and the proof is that they are confounded one with the other, and that those who are not warned of the fact take one for the other. Every time a body is perceived, as I previously explained, there are images which affix themselves to the sensation unnoticed. We think we perceive when we are really remembering or imagining. This addition of the image to the sensation is not a petty and insignificant accessory; it forms the
