It is a paradox only too readily verified that the mind as well as the body suffers in more ways than one from the acquirement of book knowledge. In the first place, the Memory, laden with an enormous mass of facts, and accustomed to shift the burden of carrying them to written notes and similar devices, loses much of its natural tenacity. The ignorant clodhopper always remembers the parish chronicles better than the scholarly parson. The old family servant, who is strongly suspected of not knowing how to write and whose spectacles are never forthcoming when there is any necessity to read, is the living annalist of the house, and was never yet known to forget an order, except now and then on purpose. Not only are the interests, and consequently the attention and retentive powers, of illiterate persons monopolized by the practical concerns of life and the tales of the past which may have reached their ears, but they have actually clearer heads, less encumbered by a multitude of irrelevant ideas, and can recall whatever they need, at a moment’s notice, without tumbling over a whole lumber-room full of rubbish to get at it. The old Rabbinical system of schooling, which mainly consisted in the committal to memory of innumerable aphorisms and dicta of sages and prophets, possessed this enormous advantage over modern instruction,—that whatever a man had so learned he possessed at his fingers’ ends, ready for instant use in every argument. But, as half the value of knowledge in practical life depends on the rapidity with which it can be brought to bear at a given moment on the point of issue, and as a ready-witted man will not merely outshine in discussion his slow-brained antagonist, but forestall and outrun him in every way, save in the labors of the library, it follows that to sacrifice the ready money of the mind for paper hard to negotiate is extremely bad economy. Mere book-learning, instead of rendering the memory more strong and agile, accustoms it to hobble on crutches. Other mental powers suffer even more than the memory by the introduction of books. That method which we familiarly call the “Rule of Thumb”—that is, the method of the Artist—is soon lost when there come to be treatises and tables of calculation to form, instead, the Method of the Mechanic. The boats of Greece are to this day _sculptured_ rather than wrought by the shipwrights, even as the old architects cut their marble architraves by the eye of genius trained to beauty and symmetry, not by the foot-rule of precedent and book-lore. The wondrous richness and harmony of coloring of Chinese and Indian and Turkish stuffs and carpets and porcelain are similarly the result, not of any rules to be reduced to formulæ, but of taste unfettered by pattern-books, unwarped by Schools of Art Manufacture, bequeathed through long generations, each acquainted intimately with the aforesaid “rule of thumb.”