76

O.65

there is an infinite variety of families of surfaces possessing these properties, except that their intersections are not straight, and to logical analysis they are equally simple. The planes and rays are only simpler in the sense of being much more in accord with the aptitudes of human thought; and they have everything and the others nothing, to do with the laws of Nature.

Far from being confined to men of science in their researches, it is, on the whole, repressed by criticism and stimulated by personal interest. I myself, who am one of the