Carlyle justly affirms, that if that man is a benefactor to the world who causes two ears of corn to grow where only one grew before, much more is he a benefactor who causes two truths to grow up together in harmony and mutual confirmation, where before only one stood solitary, and, on that side at least, intolerant and hostile. Every genius rides a winged horse; but all are apt to ride too fast. Plotinus, says Emerson, 'believes only in philosophers; Fenelon, in saints; Pindar and Byron, in poets. Read the haughty language in which Plato and the Platonists speak of all men who are not devoted to their own shining abstractions.' If genius is liable to such one-sidedness, the greater the need of educational correctives to common-place minds. Hence the overpursuit of any one subject may be hurtful, unless duly balanced by countervailing forces. As the author of _Friends in Council_ says, a human being, like a tree, if it is to attain to perfect symmetry, must have light and air given to it from all quarters. This may be done without making men superficial--without sanctioning the dissipation of mere desultory reading. One or two great branches of science may be systematically prosecuted, and others used in a more supplementary and illustrative form. 'A number of one-sided men,' observes the same writer, 'may make a great nation, though I much incline to doubt that; but such a nation will not contain a number of great men.' With the advance of intelligence, advances a catholicism of literature, of taste, of humanity at large. Uncultured intellect, 'cabined, cribbed, confined,' is ill at ease among the riches of variety in literary lore; it is satisfied with the little, because, as Menzel says, it knows not the great; it is content with one-sidedness, because it sees not the other sides. If critical _esprit de corps_ has its advantages, it has its penalties also; potent within its self-imposed bounds, it is impotent outside of them. Longfellow reminds his brethren of the lyre, that whatever is best in the great poets of all countries, is not what is national in them, but what is universal: their roots are in their native soil, but their branches wave in the unpatriotic air, that speaks the same language to all men, and their leaves shine with the illimitable light that pervades all lands. 'Let us throw all the windows open; let us admit the light and air on all sides; that we may look towards the four corners of the heavens, and not always in the same direction.'