Your quickened step, your new-found decisiveness of action, your more observant eye, your clear-cut speech instead of the former drawling utterance, your livelier manner, your freshened enthusiasm and enjoyment of life--all of these are but manifestations of a quickened intelligence.
[Sidenote: Quickened Mentality]
They are the working out through the motor paths of mental impulses to muscular action.
And these impulses to muscular action come thronging into consciousness because the livelier environment brings about a more rapid reproduction of memory pictures.
And here comes a particularly striking fact. One would naturally suppose that the more energy a man consumed, and the faster he lived, the more quickly his vitality would be exhausted and the shorter his life would be.
As a matter of fact, by the divine beneficence of Providence, your organism is so ordered as to adapt itself within certain wide limits to the demands made upon it