G.K. Chesterton on Predication, the Meaning of Is, and an Egg Being an EggSt. Thomas Aquinas (Random House: 1956), p. 121.
Against all this the philosophy of St. Thomas stands founded on the universal common conviction that eggs are eggs. The Hegelian may say that an egg is really a hen, because it is a part of an endless process of Becoming; the Berkeleian may hold that poached eggs only exist as a dream exists; since it is quite as easy to call the dream the cause of the eggs as the eggs the cause of the dream; the Pragmatist may believe that we get the best out of scrambled egos by forgetting that they ever were eggs, and only remembering the scramble. But no pupil of St. Thomas needs to addle his brains in order adequately to addle his eggs; to put his head at any peculiar angle in looking at eggs, or squinting at eggs, or winking the other eye in order to see a new simplification of eggs. The Thomist stands in the broad daylight of the brotherhood of men, in their common consciousness that eggs are not hens or dreams or mere practical assumptions; but things attested by the Authority of the Senses, which is from God.
Thus, even those who appreciate the metaphysical depth of Thomism in other matters have expressed surprise that he does not deal with what many now think the main metaphysical question; whether we can prove that the primary act of recognition of any reality is real. The answer is that St. Thomas recognised instantly, what so many modern sceptics have begun to suspect rather laboriously; that a man must either answer that question in the affirmative, or else never answer any question, never ask any question, never even exist intellectually, to answer or to ask. I suppose it is true in a sense that a man can be a fundamental sceptic, but he cannot be anything else; certainly not even a defender of fundamental scepticism. If a man feels that all the movements of his own mind are meaningless, then his mind is meaningless, and he is meaningless; and it does not mean anything to attempt to discover his meaning.