For example: by simple sense-perception we discover that one tree is taller than another, or that one tree is an elm, another a silver birch. Our perception may stop there; but not if we are in a mood to contemplate. Then the perception that one tree is taller than the other may be followed by the feeling that the taller tree gives us more satisfaction. It may seem to us to be a better proportioned tree: its parts are more pleasingly related to the whole mass; or it may seem to be in a fitter relation to the spot it occupies and to the other “objects” near it. Again, having ascertained by pure sense-impression that one tree is an elm and the other a silver birch, we may find ourselves thinking about the _qualities_ of difference presented by the two trees. With what splendid assurance the elm trunk rears up! How majestically the branches radiate from it and bear their glorious masses of abundant foliage! On the other hand, how dainty are the stems and branches of the silver birch, how delicately graceful the sprays of tiny leaves! “How sensitive!” perhaps we say. For to our imagination the slender tree may seem to be endowed with senses that respond to every movement of the air, to every glancing of the sunlight. In all these cases we have gone beyond mere sense-perception. We are no longer interested only in the “object.” Our interest has become _subjective_. We are interested in the _subject_ not the object of the verb, to perceive--the subject _who_ perceives, in this case, ourself; how the thing affects oneself; how it stirs in one a sense of beauty. By this time our thoughts may have been withdrawn from the concrete object and have passed on to “abstract” ideas, suggested by the object. It is grandeur of growth, as embodied in the elm, fragile tenderness, as expressed in the birch, that absorb our thought; and the wonder also how qualities so different can survive the rude shocks of nature, and find, each its special function in the scheme of nature’s beauty. In thus feeling external objects through our own experience of life and our own sense of beauty, we are employing the sense-perception that is specially called _æsthetic_. And it is in the degree to which objects of architecture, sculpture, or painting have the capacity of stimulating this _æsthetic appreciation_ that they properly belong in the company of the Fine Arts. * * * * * Architecture is the science and art of building structures that, while in most cases they serve a useful purpose, are in all cases designed and built with a view to beauty. Their motive is beauty as well as utility.