Mathematics and physics and chemistry and biology and psychology, not to say also the social sciences, all depend upon the far-seeing mystical visions of the mind, if not of the eye, upon the subtle, logical constructions which their would-be scientific specialism, their desire to know all things narrowly, forces upon them. Each one may be special, but each as it [p.089] gains precision and as it becomes truly an account of the facts, under the guidance of an exacting mind that at any cost must present the whole to consciousness, conserves within itself the common universe of them all by developing under what is called the "scientific imagination" all sorts of indirections, disguises, abstractions, logical constructions for the things and view-points of the others. Each to be veracious has no choice but to be also voracious, and when, for example, a physical scientist insists on seeing his world only physically, while in reality it is of course, to say no more, a world of chemical process also, and even of vital and mental character, he is sooner or later constrained to admit to his thinking what above were called abstractions or logical constructions, but what also pass under the name of "working hypotheses." These are formally true to his physical standpoint, but any outsider in order to explain why they are hypotheses that _work_ must call them compensating or conserving conceptions--in short, logical constructions that are, or that in part involve, substitutes for the neglected points of view, being, as it were, the secret agents of a universe refusing to be divided. To characterize them in just one more way, a science's working hypotheses, results as they are of science's blind but brilliant dreaming, many or all of them, are doors in the panelling by which the other sciences are quietly admitted to a room seemingly tightly closed to all comers. Every science, and this the more as it becomes scientific, must entertain all the others, however unwittingly. Tennyson's "flower in the crannied wall," so often plucked, is nothing in [p.090] all-inclusiveness when compared with a well-developed special science. No science, physical or psychical, biological or social, ever does or ever can live to itself alone. It may will to, but it does not and it cannot. All the others live with it and for it--nay, they all live in it.