1461. The merit of design consists in combining, by the hand of man, forms and objects, so as to make their effect more beautiful than if they had been left in their original position. To do this, it is necessary that the objects combined should form a whole; that is, that they should produce a single sensation on the mind, and not a succession of sensations: and this involves two principles, viz. the necessity of the unity of the whole, and the necessity of the connection of the parts that compose it.