There are four internal senses: t he imagination, the sensuous memory, the common or central or synthesizing sense, and instinct. The intellect through abstraction produces the concept. The imagination is the meeting ground between the senses and the intellect. From the phantasms in the imagination, the intellect abstracts that which is common and necessary to all the phantasms of similar objects (for example, trees or chairs); this is the essence (that which makes a tree a tree or that which makes a chair a chair). The intellectual apprehension of this essence is the general or universal concept (of a tree or a chair). A general concept is a universal idea existing only in the mind but having its foundation outside the mind in the essence which exist s in the individual and makes it the kind of thing it is. Therefore, a concept is not arbitrary although the word is. Truth has an objective norm in the real.