 which is obviously false, as would many such substitutions render the rest of the examples of II. (14) and (15) are patent logical truths; their truth depends only upon the semantic values of their logical particles. But All pediatricians are doctors and the other examples, (6)–(8) and (11)–(13), are not formal logical truths, specifiable by the logical form of the sentence (or its pattern of logical particles) alone; nor are their denials, e.g., (9) and (10), formal contradictions (i.e., of the form, where ‘p’ stands in for any sentence: “p and it is not the case that p”). How are we to capture them?