Page:Popular Science Monthly Volume 21.djvu/84

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for its nourishment, but the forces which effect this nourishment are not easily turned in other directions, and it is, therefore, a natural sequence that the body must dwindle as the power of the mind increases. The savage Teutons, whose great bodies affrighted the Romans of Cæsar, have become the civilized possessors of less bulk and more knowledge. Human energy appears not to be harmonious, but to run in grooves. Thought produces thought, and the energy once sent to the brain is the direct cause of a new demand for supplies. In like manner, the arm that is developed by work needs a larger amount of food for its maintenance. This is the explanation of the historic fact that physical and mental powers have never been proportionally cultivated, but always at the expense of each other. The profound thinker and the superior pugilist are rarely united.

But, even if it is true that the larger and healthier physique affords more blood for brain-use, it does not follow that the larger the supply the greater the amount of brain-work possible. The argument assumes that the brain has no limit to its activity except in the quantity of blood that ban be prepared for it. But it needs no scientific education to know that there are other influences which limit the thinker's activity, and that these limitations are somewhere in the mysterious recesses of the brain, or in the forces of which the brain is the organ. The physical health of the brain-worker may be perfect, his digestion unimpaired, his power to assimilate food the same, and yet he may not be able to concentrate his thoughts or carry on a complicated train of reasoning. The defect is not in his body—that is as healthy as ever; nor is it in any of the processes of blood-making—these go on as before. The trouble lies in the brain itself, whose capacity for work is measured by some hidden standard of its own, and which gives warning when a cessation of brain-work is imperative. The body is a furnace whose power of consuming fuel is greater than the capability of its boiler—the brain—to generate power. To keep the latter in good working condition, something more is necessary than building and feeding the fires. A supplementary but important consideration is, whether the steam beyond a certain point will not be productive of unpleasant consequences in the form of an explosion.

In the discussion of the collateral question, that of the effect of maternity on brain-power, Miss Hardaker's scientific logic takes its most amusing form. "The necessary outcome of absolute intellectual equality of the sexes," she says, "would be the extinction of the human race. For, if all food were converted into thought in both men and women, no food whatever could be appropriated for the reproduction of species" (page 583). What Miss Hardaker really means by this last highly scientific axiom it is impossible to guess. She can not mean that, as all food is converted into thought in men, women must cease to be mothers in order to imitate his food-conversion. Whatever Miss Hardaker may intend by her impossible supposition, the fact that ma-