Living beings not only have measurable, but also unmeasurable (psychologic) dimensions. The latter are illustrated by the directing of the myocytic locomotor apparatus. All parts of the morphologic and physiologic reflex arch obey determined psychic influences about which can be drawn conclusions upon behavior. The analysis of these influences reveals the reflex arch to be a response angle, the perception or sentiment side and the expression or feeling side of which are governed by the vertex as the switching or decision center. The origin of the two sentiments (delight and dislike) and the two feelings (hate and love) is derived biologically.