We may begin with the percept and its elements. In looking at the vase before me I see its beautiful tints, its rounded shape, its heavy pedestal with its rough curves, its solidity, weight, brittleness, and other experiences which go to make up the perception of the vase. The visual elements are given directly by the visual perceptive experience; but whence come the seemingly direct experiences of weight, heaviness, roughness, smoothness, and others of the like kind? They are evidently derived from other senses. The whole perceptive experience is of a visual character. We take in the whole with our eye. In the organic structure of the percept then, besides the experiences directly given by the stimulated sense-organ, there are other experiences, sensory in character, indirectly given, and coming from other sense organs which are not directly stimulated. The percept is a complicated dynamic product, and its elementary processes are never derived from one isolated domain of sensory experience. The activities of all the sensory domains co-operate in the total result of an apparently simple percept. Along with sensory processes directly stimulated, a mass of other sensory processes becomes organized and helps to contribute to the total result. The direct sensory elements are termed by me _primary sensory elements_; the indirectly given experiences are termed _secondary sensory elements_. The secondary sensory elements may be figuratively said to cluster round the primary sensory elements as their nucleus. The whole perceptual experience is tinged by the character of the primary elements which constitute the guiding nucleus, so to say. Thus, where the primary sensory elements are visual, the whole mass, no matter from what domain the sensory experiences are derived, appears under the form of the visual sense, and the percept is a visual percept. While the primary sensory elements form, so to say, the dynamic center of the total perceptual experience, the secondary sensory elements mainly constitute its content. Both primary and secondary elements are sensory and are induced peripherally; the primary directly, the secondary indirectly. The percept then is sensory and is constituted by primary sensory elements, or primary sensations, and by secondary sensory elements, or secondary sensations.