This function concerns only logical conceptions, but not what have been called psychological conceptions. The conception is always represented psychologically by a generalisation; and this presentation in a certain fashion is included in the conception. The generalisation represents the conception psychologically, but is not identical with it. It can, so to speak, be richer (as when I think of a triangle) or it can be poorer (the conception of a lion contains more than my generalisation of lions). The logical conception is the plumb-line which the attention tries to follow; it is the goal and pole-star of the psychological generalisation. Pure logical thought cannot occur in the case of men; it would be an attribute of deity. A human being must always think partly psychologically because he possesses not only reason but also senses, and his thought cannot free itself from temporal experiences but must remain bound by them. Logic, however, is the supreme standard by which the individual can test his own psychological ideas and those of others. When two men are discussing anything it is the conception and not the varying individual presentations of it that they aim at. The conception, then, is the standard of value for the individual presentations. The mode in which the psychological generalisation comes into existence is quite independent of the conception and has no significance in respect to it. The logical character which invests the conception with dignity and power is not derived from experience, for experience can give only vague and wavering generalisations. Absolute constancy and absolute coherence which cannot come from experience are the essence of the conception of that power concealed in the depths of the human mind whose handiwork we try hard but in vain to see in nature. Conceptions are the only true realities, and the conception is not in nature; it is the rule of the essence not of the actual existence. When I enunciate the proposition A = A, the meaning of the proposition is not that a special individual A of experience or of thought is like itself. The judgment of identity does not depend on the existence of an A. It means only that if an A exists, or even if it does not exist, then A = A. Something is posited, the existence of A = A whether or no A itself exists. It cannot be the result of experience, as Mill supposed, for it is independent of the existence of A. But an existence has been posited; it is not the existence of the object; it must be the existence of the subject. The reality of the existence is not in the first A or the second A, but in the simultaneous identity of the two. And so the proposition A = A is no other than the proposition “I am.”