The First Riddle of Induction

Abstract

What, exactly, is puzzling about induction? While the so-called problem of induction is normally introduced through David Hume’s famous argument, this essay shows how Sextus Empiricus gets to the heart of the matter. When properly understood, Sextus’ argument shows how the very power of inductive reasoning—its ability to move from particulars to universals—is at the same time what makes it “totter.” The argument has only been analyzed in any detail by the formal learning theorist Kevin Kelly, who uses the formal tools of computability theory and topology to mount a principled response. It is shown that this response depends on questionable assumptions and thus that they have not resolved Sextus’ riddle of induction.