Woodworking, hammering, swimming, rowing, walking, running, dancing are familiar activities in which the metre makes work easier and at the same time endows it will the feeling of pleasure. The proportion of action and repose—that is, the rhythm—depends upon the nature of the work. The orderly repetition or regular alternation of optical similarities or equalities dictates the rhythm of the plastic organization. In recognizing such order one learns when the next eye action is due and what particular neuromuscular adjustment will be necessary to grasp the next unit. To conserve the attentive energies of vision, therefore, the picture surface must have a temporal structure of organization—it must be rhythmically articulated in a way that corresponds, for the eye, to the rhythm of any work process.
George Kepes, Language of vision, 1944, 53.