Most, probably, of our decisions to do something positive, the full consequences of which will be drawn out over many days to come, can only be taken as the result of animal spirits — a spontaneous urge to action rather than inaction, and not as the outcome of a weighted average of quantitative benefits multiplied by quantitative probabilities.
— John Maynard Keynes, The General Theory
of Employment, Interest and Money (1936)
— Jacket art by Edward Koren from
Akerlof & Shiller, Animal Spirits (2009)