#175

Why Kant Refused to Let Hume Kill Causality

Imagine Hume watching two billiard balls clack across a table: one rolls, strikes, the next rolls away. He feels no mystical tether between them. Only the blunt sequence of impressions: motion here, motion there, side by side in space, back‑to‑back in time. If he senses “power” or “must,” he recognises it as an after‑taste brewed by repetition, not a flavour of the world itself. His verdict is severe: causality is custom, induction is faith in familiar rhythms, and every law of nature is just a polished habit. Strip those habits away and the universe lies open, perfectly free to mock yesterday’s expectations tomorrow.

Kant steps in and concedes the demolition up to a point. Yes, impressions alone never whisper “necessity,” and habits can mimic law. But he asks Hume to slow down and notice something upstream from every impression: before the first ball appears, the mind has already unfurled space and time as a grid, and the understanding has primed its own lenses, unity, plurality, even causality itself. These forms are not copied from the world; they are the scaffolding that lets there be a world of coherent objects and events. When Kant declares, “every alteration has its cause,” he is not reading a seal stamped on things; he is stating a rule without which the notion of an alteration would dissolve into noise.

Hume shakes his head: am I to believe the mind legislates nature? Kant answers that the mind legislates only appearances, not the hidden stuff‑in‑itself. His point is modest but decisive: deny those a‑priori forms and you also erase the very stage on which your empirical drama unfolds. Hume’s own talk of “habit” and “expectation” already presumes a temporal order and a sequence of events structured enough to compare; in trying to exile necessity he still smuggles in the framework that makes the exile intelligible.

So Kant refuses to let Hume kill causality not out of nostalgia for scholastic chains but because murdering the concept would also murder the possibility of knowledge. Hume’s skepticism keeps philosophy honest, forcing it to abandon airy dogmas; Kant’s transcendental turn keeps philosophy viable, showing that some rules are the price of having any experience at all. Between the two, reason gains both its humility and its backbone.