Various, Popular Science Monthly (1887)
“ We are accustomed unconsciously to recognize their prerogative in this respect when we apply the phrase 'animal spirits' to a boy who is full of life and energy, and who enjoys a run over the hills on a breezy day." All animals, also, enjoy to a full extent the pleasures connected with the perpetuation of their species and the care of their young—the latter of which are akin to some of man's mental pleasures. ”
