“It is difficult, and perhaps impossible, to give an exhaustive characterization if these objective conditions of beauty, since mind is an indispensable element within the relation and different minds are affected in various ways and by varying qualities in objects. However, considering the objective conditions of beauty by themselves alone and without reference to the perceiving mind, we may perhaps say that there is on characteristic always to be found exemplified in them; and that is unity. The beautiful object is the unified object. “It is through this unification of the object, this relating of its parts to one another, that it is grasped by the mind. There is in this an economy of effort which is essential to mental development. Therefore, it is reasonable to expect that an arrangement of the elements of an object of contemplation which aids this unification will meet the requirements of the mind better and be more acceptable than an arrangement which does not do so. Unity, can, therefore, be considered a firmly established principle of beauty.”
…This unity expresses itself mainly in three ways: unity of form, unity of content, and unity of form with content.
Here we seem to have the basal characteristic of the objective conditions of the aesthetic judgment in its purest and highest type, in so far as those conditions can be described apart from the aesthetic response itself. But, obviously, the subjective response of the mind to the objective conditions is of indispensable importance in the complete understanding of the beautiful…”
(Cunningham, The Problems of Philosophy, 362-63)