Another problem is that for many interesting assertions X, opposite(opposite(X)) does not necessarily equal X. Indeed, opposite(opposite(X)) frequently implies NOT X.
Could you give an example? I would have thought this happens with Not(opposite(X)); for example, "I don't hate you" is different than "I love you", and in fact implies that I don't. But I would have thought "opposite" was symmetric, so opposite(opposite(X)) = X.
Here's the new thread for posting quotes, with the usual rules: