Rational. Descriptive of thoughts, feelings and actions that accord with reason, an attitude based on objective values established by practical experience. (Compare irrational.)
The rational attitude which permits us to declare objective values as valid at all is not the work of the individual subject, but the product of human history.
Most objective values-and reason itself-are firmly established complexes of ideas handed down through the ages. Countless generations have laboured at their organization with the same necessity with which the living organism reacts to the average, constantly recurring environmental conditions, confronting them with corresponding functional complexes, as the eye, for instance, perfectly corresponds to the nature of light. . . . Thus the laws of reason are the laws that designate and govern the average, “correct,” adapted attitude. Everything is “rational” that accords with these laws, everything that contravenes them is “irrational.”[Definitions,” Ibid, par. 785f.]
Jung described the psychological functions of thinking and feeling as rational because they are decisively influenced by reflection.