_Now my first thesis is that this element, discernible in each and every sensation, though more developed in some than in others, is the original sensation of space,_ out of which all the exact knowledge about space that we afterwards come to have is woven by processes of discrimination, association, and selection. 'Extensity,' as Mr. James Ward calls it,[143] on this view, becomes an element in each sensation just as intensity is. The latter every one will admit to be a distinguishable though not separable ingredient of the sensible quality. In like manner extensity, being an entirely peculiar kind of feeling indescribable except in terms of itself, and inseparable in actual experience from some sensational quality which it must accompany, can itself receive no other name than that of _sensational element_. It must now be noted that _the vastness hitherto spoken of is as great in one direction as in another_. Its dimensions are so vague that in it there is no question as yet of surface as opposed to depth; 'volume' being the best short name for the sensation in question. _Sensations of different orders are roughly comparable, inter se, with respect to their volumes._ This shows that the spatial quality in each is identical wherever found, for different qualitative elements, e.g. warmth and odor, are incommensurate. Persons born blind are reported surprised at the largeness with which objects appear to them when their sight is restored. Franz says of his patient cured of cataract: "He saw everything much larger than he had supposed from the idea obtained by his sense of touch. Moving, and especially living, objects appeared very large."[144] Loud sounds have a certain enormousness of feeling. It is impossible to conceive of the explosion of a cannon as filling a small space. In general, sounds seem to occupy all the room between us and their source; and in the case of certain ones, the cricket's song, the whistling of the wind, the roaring of the surf, or a distant railway train, to have no definite starting point. In the sphere of vision we have facts of the same order. 'Glowing' bodies, as Hering says, give us a perception "which seems _roomy_ (_raumhaft_) in comparison with that of strictly surface color. A glowing iron looks luminous through and through, and so does a flame."[145] A luminous fog, a band of sunshine, affect us in the same way. As Hering urges: