informing of eye and hand rather than by the straining of thought and memory. Unlike quantity, tension is not immediately dependent upon physical health. Neuralgic and dyspeptic persons often possess this virtue in high degree, and indeed fasting is said by spiritual teachers to intensify mental action. If quantity, however, be not added to tension, great passion or great action is followed by utter exhaustion and depression; and, where high mettle and enduring force are combined, we obtain the greatest results. Certain drugs, such as strychnine, have the property of heightening the tension of nerve; and others, such as iron and cod-liver oil, of enriching it in quantity. In the combination of the two kinds we have the most precious medicines. The so-called "nervous children"—products of a later civilization—need especially the benefits of quantity and control, and intelligent parents secure this by restraining scholastic pressure, by enforcing a regular discipline, and by encouraging physical development.
That endowment which I have called Variety or versatility is also partly innate and partly acquired, but chiefly innate. It must consist in the accretion of a greater number of ganglia and of interweaving fibres. This is not unfavorable to quantity of nerve-force, but perhaps it is unfavorable to the quality or high development of special ganglionic groups, and also to tenacity or steadfast intensity. The schoolmaster therefore abhors versatility, and that greater schoolmaster, the world, grinds it to dust. Without variety the pedant loses the sense of the infinite interests and conditions of life; with variety and without penetration the dilettante is ignorant of the depths of his own ignorance. The pedant denies that any knowledge should be taken in small quantities, the dilettante is repelled by the isolation of limited research. It would seem to be the aim of good education to insist upon a mastery of one or more subjects, that the grown man should be able to fight with the foremost, to concentrate his powers, and to realize what knowledge is, but that at the same time he should gain some not inadequate notion of the whole field of the battle of life. He will thus gain in sympathy and flexibility of mind, while he is saved from the "failing of omniscience." A happy citizen of the republic of learning must have culture at once liberal and profound, at once general and special; to such a one a little knowledge is no longer a dangerous thing.
Finally, Control is partly innate, but greatly the creature of education. It is, I believe, the earliest work of education, the safest work and the most abiding. As an innate virtue it consists, no doubt, in the superposition of more complex or higher centres upon the lower and upon the weaving of these together by commissures of various orders. These ganglia and fibres, sketched out as it were by inheritance, are nourished and developed by use, i. e., by education. By use
- Diderot is the most brilliant instance of the Various man I can at present call to mind.