The continual transitions do not permit us to speak of the ‘individual’, etc.; the ‘number’ of beings is itself in flux. We wouldn’t speak of time at all and would know nothing of motion if we didn’t, in a crude way, believe we saw something ‘at rest’ alongside things in motion. Just as little would we speak of cause and effect, and without the erroneous conception of the ’empty space’ we would never have arrived at the conception of space itself. The principle of identity has as its background the ‘appearance’ that things are the same. A world of becoming could not, in the strict sense, be ‘grasped’, be ‘known’; only inasmuch as the ‘grasping’ and ‘knowing’ intellect finds an already created, crude world, cobbled together out of deceptions but having become solid, inasmuch as this kind of illusion has preserved life – only to that extent is there such a thing as ‘knowledge’: i.e., a measuring of earlier and more recent errors against one another.
Notebook 36, June – July 1885, paragraph 23