Literature in general, when we attempt to define it, becomes as elusive as the highest of its forms, which is poetry. Literature reflects life, in all its phases, to use a trite comparison, as some of the old Gothic cathedrals reflect life — from the agonizing figure on the rood screen to the grinning gargoyles on the roof and the vile little demons — the seven deadly sins — carved on the backs of the remote stalls. It has its spires that spring up as high as the clouds, and its crawling things of the earth, symbolical of the vices of the people that produce it. Its form changes, not only with every great impulse of force, but with every slight change of emotion. It expresses, it illuminates, it interprets; it cannot exist without thought, but it is more than thought. It is not philosophy, but it is impregnated with the effects of philosophy. It is not logic or metaphysics, or ethics; but it cannot exist in perfection without a logical basis — and it partakes of metaphysics and ethics. It is neither scientia in the old sense — for pure and colorless truth cannot be literature — or science in the new; yet it exists through truth, and its phenomena are best explained by the methods of science. It is not history, yet it is the beginning of history. It is not the personal word alone, yet the personal word is necessary to its existence. As I said, it is not ethics, yet it expresses the morality of the nation whose life it interprets. It is minutely personal — personality is one of its essences, and yet it represents better than anything else the national life.
(Maurice Francis Egan, “The Definition of Literature,” The Catholic University Bulletin, Vol. VIII, 1902, pp. 429–430).