Georg Wilhelm Friedrich Hegel,
The Logic of Hegel
“ There the several organs and functions are similarly seen to stand to each other in the relation of reciprocity. Reciprocity is undoubtedly the proximate truth of the relation of cause and effect, and stands, so to say, on the threshold of the notion; but on that very ground, supposing that our aim is a thoroughly comprehensive idea, we should not rest content with applying this relation. If we get no further than studying a given content under the point of view of reciprocity, we are taking up an attitude which leaves matters utterly incomprehensible. ”
