The birth of a new æsthetic experience depends on the maintenance of two principles by the creative purpose:
1. The novel consequent must be graded in relevance so as to preserve some identity of character with the ground.
2. The novel consequent must be graded in relevance so as to preserve Some contrast with the ground in respect to that same identity of character.
These two principles are derived from the doctrine that an actual fact is a fact of æsthetic experience. All æsthetic experience is feeling arising out of the realization of contrast under identity.
Thus the consequent must agree with the ground in general type so as to preserve definiteness, but it must contrast with it in respect to contrary instances so as to obtain vividness and quality. In the physical world, this principle of contrast under an identity expresses itself in the physical law that vibration enters into the ultimate nature of atomic
