The unity of the social mind consists not in agreement but in organization, in the fact of reciprocal influence or causation among its parts, by virtue of which everything that takes place in it is connected with everything else, and so is an outcome of the whole. Whether, like the orchestra, it gives forth harmony may be a matter of dispute, but that its sound, pleasing or otherwise, is the expression of a vital cooperation, cannot well be denied.[112] Professor Cooley stresses the unconscious character of many of these social relations. "Although the growth of social consciousness is perhaps the greatest fact of history, it has still but a narrow and fallible grasp of human life." Cooley objects to the Cartesian postulate, which makes "_cogito_," "I think," the fundamental and most absolutely certain fact in the world. He holds that it grows out of the idiosyncrasy of a highly specialized, introspective philosopher's mind, and that, for the normal mind, "_cogitamus_," "we think," is just as obvious.[113] The "I" feeling, and the "we" feeling are differentiated together out of the inchoate experience of the child. And "I" and "we" are alike social in their nature. The self, for Professor Cooley, is not a scholastic "soul-substance" or transcendental ego, but simply a relatively differentiated portion of the social mind. "'Social organism' using the term in no abstruse sense, but merely to mean a vital unity in human life, is a fact as obvious to enlightened common sense as individuality."[114] I pause here to contrast this view of the "social mind" with that of some other writers, of whom I may take Professor Giddings as representative. I quote from page 134 of the 1905 edition of Professor Giddings' _Principles of Sociology_:-- The social mind is the phenomenon of many individual minds in interaction, so playing upon one another that they simultaneously feel the same sensation or emotion, arrive at one judgment and perhaps act in concert. It is, in short, the mental unity of many individuals, or of a crowd.