Knowing How vs. Knowing That

In his 1945 Presidential Address to the Aristotelian Society, Ryle distinguished two forms of knowledge that the Western philosophical tradition had treated as variants of a single thing. Knowing that is propositional: facts that can be stated in sentences, tested on examinations, written in textbooks. Knowing how is practical: competences exhibited in performance, exercised in the doing, and irreducible to any set of propositions about the doing. The bicycle rider does not consult a mental list of rules before each pedal stroke. The chess player does not apply a theory of strategy; she plays strategically, and the theory (if formulated at all) is an abstraction from her already-competent practice. Ryle's great insight — that knowing how is not reducible to knowing that, because intelligent application of any rule requires prior intelligent competence that no rule can supply — turns out to be the single most consequential philosophical distinction for the AI age.