A concept’s negation is logically distinct from its paired opposite.

Evidence

I make a sharp distinction between the “negation” and the “opposite.” The negation is signaled by “not-” or the negation symbol (¬) from mathematical logic. The opposite appears in concept pairs, where one concept is seen as the opposite of the other, but it is very different from the negation. — Gary Goertz, Social Science Concepts and Measurement, 616

Categorization

• DEFINE: Draws a technical line between ‘not-X’ and ‘the opposite of X,’ a distinction most writers collapse.
• SEED: Angle: an essay on how ordinary argument treats ‘not-democratic’ and ‘authoritarian’ as synonyms when logic says otherwise.