In order that the concept of substance could originate--which is indispensable for logic although in the strictest sense nothing real corresponds to it--it was likewise necessary that for a long time one did not see or perceive the changes in things. The beings that did not see so precisely had an advantage over those who saw everything "in flux." At bottom, every high degree of caution in making inferences and every skeptical tendency constitute a great danger for life. No living beings would have survived if the opposite tendency--to affirm rather than suspend judgment, to err and make up things rather than wait, to assent rather than negate, to pass judgment rather than be just-- had not been bred to the point where it became extraordinarily strong.