Thus to him, to this school-boy under the bending dome of day, is suggested that he and it proceed from one Root; one is leaf and one is flower; relation, sympathy, stirring in every vein. And what is that root? Is not that the soul of his soul?--A thought too bold?--A dream too wild? Yet when this spiritual light shall have revealed the law of more earthly natures,--when he has learned to worship the soul, and to see that the natural philosophy that now is, is only the first gropings of its gigantic hand,--he shall look forward to an ever-expanding knowledge as to a becoming creator.[13] He shall see that nature is the opposite of the soul, answering to it part for part. One is seal and one is print. Its beauty is the beauty of his own mind. Its laws are the laws of his own mind. Nature then becomes to him the measure of his attainments. So much of nature as he is ignorant of, so much of his own mind does he not yet possess. And, in fine, the ancient precept, "Know thyself,"[14] and the modern precept, "Study nature," become at last one maxim. * * * * * II. The next great influence into the spirit of the scholar is the mind of the Past,--in whatever form, whether of literature, of art, of institutions, that mind is inscribed. Books are the best type of the influence of the past, and perhaps we shall get at the truth,--learn the amount of this influence more conveniently,--by considering their value alone. The theory of books is noble. The scholar of the first age received into him the world around; brooded thereon; gave it the new arrangement of his own mind, and uttered it again. It came into him life; it went out from him truth. It came to him short-lived actions; it went out from him immortal thoughts. It came to him business; it went from him poetry. It was dead fact; now, it is quick thought. It can stand, and it can go. It now endures, it now flies, it now inspires.[15] Precisely in proportion to the depth of mind from which it issued, so high does it soar, so long does it sing. Or, I might say, it depends on how far the process had gone, of transmuting life into truth. In proportion to the completeness of the distillation, so will the purity and imperishableness of the product be. But none is quite perfect. As no air-pump can by any means make a perfect vacuum,[16] so neither can any artist entirely exclude the conventional, the local, the perishable from his book, or write a book of pure thought, that shall be as efficient, in all respects, to a remote posterity, as to contemporaries, or rather to the second age. Each age, it is found, must write its own books; or rather, each generation for the next succeeding. The books of an older period will not fit this.