The matter is simple enough if we look at it freed from the obscurity with which philosophers have surrounded it. Thought is a complex fact, the joint product of subject and object. God is his own object, because he is self existent and self-sufficing: is in himself, as say the theologians, _actus purissimus_, most pure act, which permits us up to a certain point to understand the eternal generation of the Son and the procession of the Holy Ghost. God, being self-existent and self-sufficing, needs and can receive nothing from without his own most perfect being. But man is a dependent being, a creature, and does not and cannot suffice in himself for either his own existence or his own intelligence. He cannot think by himself alone or without the concurrence of the object, which is not himself. If the concurrence of the object be essential to the production of my thought, then that concurrence must be active, for a passive concurrence is the same as no concurrence at all. Then the object must be active, therefore real, for what is not real cannot act or be active. Then the object in my thought is not and cannot be myself, but stands over against me. Now, I know that I think these ideas, and that they are the object in my thought without which I cannot think at all. Therefore, they are objective and real, and neither myself nor my creations, as are abstractions. This conclusion is questioned only by those persons who have not duly considered the fact that there can be no thought without both subject and object, and that man can never be his own object. To assume that he can act, think, or know with himself alone, without the concurrence of that which is not himself and is independent of him, is to deny his dependence and to assume him to be God--a conclusion which some think follows from the famous "_Cogito, ergo sum_" of Descartes, and which is accepted and defended by the whole German pantheistic school of the present day. {156} Indeed, as atheism was in the last century, so pantheism is in the present century the real enemy philosophy has to combat. In concluding the reality of the object from the fact that I think it, I am far from pretending that thought cannot err; but the error is not in regard to what I really think, but in regard to that which I do not think, but infer from my thought. I think only what is intelligible, and what is intelligible is real, and therefore true, for falsehood, being unreal, is unintelligible, and therefore cannot be thought. But in converting my thought into a proposition, I may include in the proposition not only what I thought, but what I did not think. Hence the part of error, which is always the part not of knowledge, but of ignorance. It is so we understand St. Augustine and St. Thomas.[Footnote 37]