So, naturalists observe, a flea; Hath smaller fleas that on him prey; And these have smaller fleas to bite 'em, And so proceed ad infinitum.
Jonathan SwiftIn all assemblies, though you wedge them ever so close, we may observe this peculiar property, that over their heads there is room enough; but how to reach it is the difficult point. To this end the philosopher's way in all ages has been by erecting certain edifices in the air.
Jonathan Swift