Pygmies and Giants
Now, all this involves clearly enough a greatly increased rate of activity on the part of the bodily organs of assimilation and repair. It is a situation on all fours with that of the countryman whose rate of brain activity has been stimulated by an increased mental demand.
No man will maintain that better, more nourishing and more liberal food rations, transformed into increased bodily tissue, with a consequent greater weight and greater muscular strength, would result in a loss of vitality or the shortening of a man's life.
Transforming Inertness into Alertness
Pygmies cannot become giants physically or intellectually. But as the puny youth can by systematic exercise broaden his frame and develop his muscles into at least a semblance of the athlete, and can then through his healthier appetite and his faster rate of repair maintain himself without effort at the new standard; so can the mentally inert call forth their reserves of energy and maintain a higher standard of activity and fruitfulness.
Few men live on the plane of their highest efficiency. Few search the recesses of the well-springs of power. The lives of most of us are passed among the shallows of the mind without thought of the possibilities that lurk within the deeper pools.
How the Mind Accumulates Energy