The most valuable function of standard authors lies in their quickening influence upon the intellectual life. The effort to appropriate their ideas and to master their thoughts is the best possible exercise for the understanding. In thinking their thoughts, weighing their arguments, and following their train of reasoning the mind gains vigor, strength, and the capacity for sustained effort. The invigorating atmosphere which a great thinker creates has a most remarkable tonic effect upon all who dwell in it. By unconscious absorption they acquire his spirit of inquiry, his methods of research, his habits of investigation, his way of attacking and mastering difficulties. While trying to walk in his footsteps they learn to take giant strides. His idioms, his choice of words, his favorite phrases and expressions are at their service when they enter new fields of truth. Both in power and aspiration they become like him through the mysterious process of mind acting upon mind, of heart evoking heart, and of will transfusing itself into will. A great thinker gets his place in the galaxy of shining intellects through the truths which he communicates; and as truth is the best food for the soul, so the quest of truth is the best exercise for all its faculties.
[Sidenote: The literature of knowledge and the literature of power.]
De Quincey, in his essay on Alexander Pope, draws an important and oft-quoted distinction between the literature of knowledge and the literature of power. He says the function of the one is to teach, of the other to move. The former he likens to a rudder, the latter to an oar or a sail. To illustrate the difference he asks, “What do you learn from ‘Paradise Lost’? Nothing at all. What do you learn from a cookery-book? Something new, something that you did not know before, in every paragraph. But would you, therefore, put the wretched cookery-book on a higher level of estimation than the divine poem? What you owe to Milton is not any knowledge, of which a million separate items are still but a million of advancing steps on the same earthly level; what you owe is _power_,—that is, exercise and expansion to your own latent capacity of sympathy with the infinite, where every pulse and each separate influx is a step upward, a step ascending, as upon Jacob’s ladder, from earth to mysterious altitudes above the earth. All the steps of knowledge, from first to last, carry you farther on the same plane, but could never raise you one foot above your ancient level of earth; whereas, the very first step in power is a flight, is an ascending into another element where earth is forgotten.”