Paradox

AUGUSTINE’S PRAGMATIC PARADOXES 169Augustine also believes that we can know tautologiessuch as “If Cicero executed the Catliniarian conspirators, thenCicero executed the Catliniarian conspirators.” Sextus neverbothers to attack tautologies because he does not considerthem to be assertions. They do not try to match appearanceto reality. When people talk about the weather, they do notpredict “Either it will rain or not.” Tautologies are emptyremarks akin to the schema “Either____or not___.” If youcannot get it wrong, you cannot get it right!But Augustine is right. People do mistakenly rejecttautologies and mistakenly accept contradictions. In a reductioad absurdum, you demonstrate that the suppositionimplies a contradiction and, on that basis, you assert thenegation of the supposition. Sextus often seems to assume thathe can block proofs merely by refusing to grant premises. Butmany philosophical arguments do not employ premises; theyjust use inference rules. Indeed, Sextus’s own internal criticismsare indirect arguments of this sort. When he usesconditional proof, he concludes by asserting a conditionalproposition even though he never asserted a premise.Augustine’s third class of certainties (in addition toreports of appearances and tautologies) involve pragmaticparadoxes. If Augustine were to say “I am dead,” then hisassertion would be a pragmatic contradiction. But it cannotbe a semantic contradiction because when I say “Augustineis dead,” I utter a truth.The opposite of a pragmatic contradiction is a pragmatictautology. My utterance of “I am awake” is vindicated by myvery act of asserting it. Augustine believed that pragmatictautologies could be turned into a reply to the skeptic.Academic Skeptics argued that every judgment about whatexists is fallible because it is always the case that one might