189. Degrees of height are homogeneous, with one following after another in succession, like end, cause and effect. Since degrees of breadth or continuous degrees are like those in a progression of light to dark, of heat to cold, of hard to soft, of dense to rare, of thick to thin, and so on, and these degrees are known from sense experience and visual observation, whereas degrees of height or discrete degrees are not, therefore we must deal chiefly with the latter in this part of the work; for without a concept of these latter degrees, one cannot see causes. People know, indeed, that end, cause and effect follow in order as prior, subsequent and last elements. They also know that the end produces the cause, and through the cause, the effect, in order that the end may be realized. And they know many other things relating to these three as well. Yet to know these things and not see them in application to actual phenomena is to know only abstractions- abstractions which remain in the thought only as long as one contemplates the analytical speculations of metaphysical philosophy. So it is that although end, cause and effect proceed by discrete degrees, still little if anything is known in the world about these degrees. For a concept only of abstractions is like some airy apparition which flies away; but if abstractions are applied to such phenomena as have actual existence in the world, they are like something visible to the eyes in the world, which stays in the memory.