practical relations. That ideal object is thereby endowed with as many qualities and powers as I had associable sensations of which to make it up. This object is a concretion of my perceptions in space, so that the redness, hardness, sweetness, and roundness of the apple are all fused together in my practical regard and given one local habitation and one name.
This kind of synthesis, this superposition and mixture of images into notions of physical objects, is not, however, the only kind to which perceptions are subject. They fall together by virtue of their qualitative identity even before their spatial superposition; for in order to be known as repeatedly simultaneous, and associable by contiguity, they must be associated by similarity and known as individually repeated. The various recurrences of a sensation must be recognised as recurrences, and this implies the collection of sensations into classes of similars and the apperception of a common nature in several data. Now the more frequent a perception is the harder it will be to discriminate in memory its past occurrences from one another, and yet the more readily will its present recurrence be recognised as familiar. The perception in sense will consequently be received as a repetition not of any single earlier sensation but of a familiar and generic experience. This experience, a spontaneous reconstruction based on all previous sensations of that kind, will be the one habitual idea with which