extensity

Extensity as an element in the complex of extension must be carefully distinguished from intensity.

The elementary undifferentiated sensation excited by the stimuli exerted by a continuous whole is known as its “extensive quantity” or “extensity.”

Mere increase of pressure implies increase of intensity of sensation; to increase the extensity the area, so to speak, of the exciting stimulus must be increased.

It should be observed that this application of the idea of extensity to sensation in general, rather than to the matter which is the exciting stimulus, is only an analogy, an attempt to explain a common psychic phenomenon by terminology which is intrinsically suitable to the physical.

This catholic spirit of friendliness is delightful and attractive in many ways, but it has its drawbacks; it is not possible perhaps to have both extensity and intensity of emotion.