our lives; fail, more or less, to obey the counsels of experience and wisdom, and we fritter our strength away in desultory and intermittent efforts among which we lose the habit of systematic labor directed to definite objects. The faculties of the mind, like the organs of the body, grow and are strengthened by appropriate use, but if allowed to remain idle become dull and sluggish, and may even undergo a sort of degeneration or atrophy. But a due variety and proportion of mental gymnastics tends to preserve them in harmony with one another and ready to co-operate in all the work they are fitted to perform.
The examples are many of naturalists, and mathematicians, and astronomers, and scientists in general, who have so warped and dwarfed their minds as no longer to have any relish for the beautiful in nature or art, or for those moral qualities by which human nature is raised higher than by all the dialects of the schools, the problems of mathematics, or even of the questions that concern organic life. The ancients bade us to "beware of the man of one book," not, perhaps, so much because he was apt to be supremely strong within the limited range of its special subject, and, therefore, to be avoided as its champion, but rather because its study would have tended to dwarf and weaken and emasculate those other faculties by means of which he could harmonize with his fellow-men, or oppose them in honorable conflict. No, the larger the range of one's knowledge and one's interests, at so many the more points will he touch his fellow-men in sympathy, and impart, as well as receive, the greater number of those ideas and sentiments that "make the whole world kin."
