Turn back for a moment to the page upon which his theory is quoted, and read the last sentence. Is his utterance a "principle," or is it a judgment? Is it an axiom, or is it a guess. The logician asserts that we know only the conditioned, and yet bases his assertion upon "the principles," &c. What is a principle, and how is it known? If it is axiom, then he has denied his own philosophy in the very sentence in which he uttered it. And this, we have no hesitation in saying, is just what he did. He blindly assumed certain "fundamental laws of thought,"--to quote another of his phrases--to establish the impotence of the mind to know those laws _as fundamental_. Again, if his philosophy is valid, the words "must," "necessary," and the like are entirely out of place; for they are unconditional. In the conditioned there is, can be, no must, no necessity. From these excursions about the principle let us now return to the principle itself. It may be stated concisely thus: There are two extremes,--"the Absolute" and the "Infinite." These include all being. They are contradictories, that is, one must be, to the exclusion of the other. But the mind can "conceive" of neither. What, then, is the logical conclusion? _That the mind cannot conceive of anything._ What is his conclusion? That the mind can conceive of something between the infinite and the absolute, which is neither the one nor the other, but a _tertium quid_--the conditioned. Where did this _tertium quid_ come from, when he had already comprehended everything in the two extremes? If there is a mean, the conditioned, and the two extremes, then "excluded middle" has nothing to do with the matter at all. To avoid the inevitable conclusion of his logic as just stated, Hamilton erected the subterfuge of _mental imbecility_. To deny any knowledge to man, was to expose himself to ridicule. He, therefore, and his followers after him, drew a line in the domain of knowledge, and assigned to the hither side of it all knowledge that can come through generalizations in the Understanding; and then asserted that the contradictions which appeared in the mind, when one examined those questions which lie on the further side of that line, resulted from the impotency of the mind to comprehend the questions themselves. This was, is, their psychology. How satisfactory it may be to Man, a hundred years, perhaps, will show. But strike out the last assertion, and write, Both are cognizable; and then let us proceed with our reasoning. The essayist in the North American presents the theory under four heads, as follows:-- "1. The Infinite and Absolute as defined, are contradictory and exclusive of each other; yet, one must be true. "2. Neither of them can be conceived as possible. "3. Each is inconceivable; and the inconceivability of each is referable to the same cause, namely, mental imbecility. "4. As opposite extremes, they include everything conceivable between them."