Sec. 23. Symmetry is evidently a kind of unity in variety, where a whole is determined by the rhythmic repetition of similars. We have seen that it has a value where it is an aid to unification. Unity would thus appear to be the virtue of forms; but a moment's reflection will show us that unity cannot be absolute and be a form; a form is an aggregation, it must have elements, and the manner in which the elements are combined constitutes the character of the form. A perfectly simple perception, in which there was no consciousness of the distinction and relation of parts, would not be a perception of form; it would be a sensation. Physiologically these sensations may be aggregates and their values, as in the case of musical tones, may differ according to the manner in which certain elements, beats, vibrations, nervous processes, or what not, are combined; but for consciousness the result is simple, and the value is the pleasantness of a datum and not of a process. Form, therefore, does not appeal to the unattentive; they get from objects only a vague sensation which may in them awaken extrinsic associations; they do not stop to survey the parts or to appreciate their relation, and consequently are insensible to the various charms of various unifications; they can find in objects only the value of material or of function, not that of form. Beauty of form, however, is what specifically appeals to an aesthetic nature; it is equally removed from the crudity of formless stimulation and from the emotional looseness of reverie and discursive thought. The indulgence in sentiment and suggestion, of which our time is fond, to the sacrifice of formal beauty, marks an absence of cultivation as real, if not as confessed, as that of the barbarian who revels in gorgeous confusion. The synthesis, then, which constitutes form is an activity of the mind; the unity arises consciously, and is an insight into the relation of sensible elements separately perceived. It differs from sensation in the consciousness of the synthesis, and from expression in the homogeneity of the elements, and in their common presence to sense. The variety of forms depends upon the character of the elements and on the variety of possible methods of unification. The elements may be all alike, and their only diversity be numerical. Their unity will then be merely the sense of their uniformity.[6] Or they may differ in kind, but so as to compel the mind to no particular order in their unification. Or they may finally be so constituted that they suggest inevitably the scheme of their unity; in this case there is organization in the object, and the synthesis of its parts is one and pre-determinate. We shall discuss these various forms in succession, pointing out the effects proper to each. _Multiplicity in uniformity._