but I might have used other types of unification, each of which has its unique feeling tone, as I shall show presently, after I have analyzed them. Keeping in mind the motives which explain the structure of works of art, I wish now to distinguish and describe the chief types. There are, I think, three of these, of which each one may include important special forms--unity in variety, dominance, and equilibrium. Unity in variety was the earliest of the types to be observed and is the most fundamental. It is the organic unity so often referred to in criticism. It involves, in the first place, wholeness or individuality. Every work of art is a definite single thing, distinct and separate from other things, and not divisible into parts which are themselves complete works of art. No part can be taken away without damage to the whole, and when taken out of the whole, the part loses much of its own value. The whole needs all of its parts and they need it; "there they live and move and have their being." The unity is a unity of the variety and the variety is a differentiation of the unity.[Footnote: Cf. Lipps: _Aesthetik_, Bd. I, Drittes Kapitel.] The variety is of equal importance with the unity, for unity can assert itself and work only through the control of a multiplicity of elements. The analogy between the unity of the work of art and the unity of the organism is still the most accurate and illuminating. For, like the work of art, the body is a self-sufficient and distinctive whole, whose unified life depends upon the functioning of many members, which, for their part, are dead when cut away from it.