Even those who hold the opinion just rejected—that the purely possible essence as such has no reality in any conceivable sense—would presumably admit that it is an object of human thought at all events; they would accord to it the being it has from the human mind which thinks it. It would therefore be an _ens rationis_ according to this view, having only the ideal being which consists in its being constituted and contemplated by the human mind. That it has the ideal being, the _esse ideale_ or _esse intentionale_, which consists in its being contemplated by the human mind as an object of thought, no one will deny. But a little reflection will show, firstly, that this ideal being is something more than the ideal being of an _ens rationis_, of a mere logical entity; and, secondly, that a possible essence must have some other ideal being than that which it has in the individual human mind. The possible essence is not a mere logical entity; for the latter cannot be conceived as capable of existing apart from the human mind, in the world of actual existences (3), whereas the former can be, and is in fact, conceived as capable of such existence. Its ideal being in the human mind is, therefore, something other than that of a mere logical entity. The ideal being which it has in the human mind as an object of thought is undoubtedly derived from the mind’s knowledge of actual things. We think of the essences of actually experienced realities apart from their actual existence. Thus abstracted, we analyse them, compare them, reason from them. By these processes we can not merely attain to a knowledge of the actual existence of other realities above and beyond and outside of our own direct and immediate intuitional experience, but we can also form concepts of multitudes of realities or essences as intrinsically possible, thus giving these latter an ideal existence in our own minds. Here, then, the question arises: Is this the only ideal being that can be ascribed to such essences? In other words, are essences intrinsically possible because _we think_ them as intrinsically possible? Or is it not rather the case that we think them to be intrinsically possible because they are intrinsically possible? Does our thought constitute, or does it not rather merely discover, their intrinsic possibility? Does the latter result from, or is it not rather presupposed by, our thought-activity? The second alternative suggested in each of these questions is the true one. As our thought is not the source of their actuality, neither is it the source of their intrinsic possibility. Solipsism is the _reductio ad absurdum_ of the philosophy which would reduce all _actuality_ experienced by the individual mind to phases, or phenomena, or self-manifestations, of the individual mind itself as the one and only actuality. And no less absurd is the philosophy which would accord to all _intrinsically possible_ realities no being other than the ideal being which they have as the