A man going quietly about his business all day long expends far more muscular energy than an athlete who lifts a huge weight once a day. This has been proved physiologically, and so the social sum total of everybody's little everyday efforts, especially when added together, doubtless releases far more energy into the world than do rare heroic feats. This total even makes the single heroic feat look positively minuscule, like a grain of sand on a mountaintop with a megalomaniacal sense of its own importance.
