Hello, Todd. You wrote: (1) "'Examples of complementary predicates are listed in predicate pairs (6) through (10). (6) caucasian/noncaucasian (7) healthy/nonhealthy (8) excellent/nonexcellent (9) capitalist/noncapitalist (10) friend/nonfriend' Is this your personal definition? Or a formal definition?" The terms "complementary predicate" and "contrary predicate" are used by an author of a logic textbook, Todd. You wrote me the question: (2) "Do you think the pair (for example) healthy/nonhealt[h]y and the pair healthy/not healthy are identical? By identical, I mean the same in the experience of the listener to these utterances." And my answers are (3) through (5). (3) It would depend on the listener.  (4) The pairs unhealthy/healthy, not healthy/healthy, and nonhealthy/healthy, are pairs for which any combination of two is nonidentical, by American English convention.  (5) The limits of your vocabulary determine whether you find some actual English words unfamiliar.  (6) Prefixing 'non' to some words can extend your vocabulary. I should have included a discussion of points (5) and (6) in my original write-up. (7) To be not healthy is definitely to be nonhealthy, and maybe to be unhealthy.  To say that someone is unhealthy is to say that he is ill.  To say that someone is not healthy MIGHT be to say that he is ill, but the term "not healthy" could mean other things, in common American English usage. (8) The meaning of the words "unhealthy" and "healthy" are not disputed, but an unusual term, like "nonhealthy", can be outside a hearer's vocabulary, and, so, disputable. I hope statements (4) and (7) answer your questions about differences between usage of the terms  "healthy", "nonhealthy" and "not healthy". If I were to write an article version of my discussion, I would include references, an abstract, and some information on the cultural standards that let English speakers use affixes with common words.  I would also index much less of the article content than I would index in my post content. (9) "You've really got some poor premises in here." Thank you for your partial feedback on my premises.  I will welcome your full analysis of the arguments whose premises you find poor.  You are free to standardize, and then post to me, those arguments of mine whose premises you find poor.  Your full analysis could help me write my article. (10) "Where, specifically, in the world of experience ... would this stuff prove useful?" (11) Given that you appreciate a difference between acceptable, poor, and nonacceptable premises, you could elucidate, for me, any differences you find between my nonacceptable premises (my not acceptable premises), and my  poor premises.  I hope to read a product of your performing action (11). -nj ps: Be advised that you need a good understanding of informal logic to perform action (11).  You might need to take a college class before you perform action (11). Maybe all you need is a library! Look on the shelves for a logic textbook that has answers in the back.