Similarities are read into nature by our nervous system, and so are structurally less fundamental than differences. Less fundamental, but no less important, as life and 'intelligence' would be totally impossible without abstracting. It becomes clear that the problem which has so excited the s.r. of the people of the United States of America and added so much to the merriment of mankind, 'Is the evolution a ''fact'' or a ''theory''?, is simply silly. Father and son are never identical - that surely is a structural 'fact' - so there is no need to worry about still higher abstractions, like 'man' and 'monkey'. That the fanatical and ignorant attack on the theory of evolution should have occured may be pathetic, but need concern us little, as such ignorant attacks are always liable to occur. But that biologists should offer 'defences' based on the confusions of orders of abstractiobs, and that 'philosophers' should have failed to see the simple dependence is rather sad. The problems of 'evolution' are verbal and have nothing to do with life as such, which is made up all through of different individuals, 'similarity' being structurally a manufactured article, produced by the nervous system of the observer.
Alfred Korzybski, Science and Sanity: An Introduction to Non-Aristotelian Systems and General Semantics
abstraction, biology, similarity