This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1873 edition. Excerpt: ...to convince us, as similar principles did Humboldt, that we grasp principles of sublime simplicity and certainty. Those who accept the proportional theory of education, may perhaps, for some time yet be ridiculed as doctrinaires, but as no one can expect to be practically useful unless he first be theoretically correct, we must still cogitate and await the verdict of the future....