Hume shows us that induction can’t be justified by reason—i.e. by deduction or induction—so us undergraduates like to put induction and deduction side by side as the two fundamental ways of reasoning. Fine. It seems clear that we can’t reduce induction to deduction; people have tried but it doesn’t tend to work. But I think it might be possible to reduce our reliance upon deduction to induction: we have this magical faculty that makes mistakes but generally only feels certain when it’s actually got things right, and we learn to judge this throughout our school Maths lessons, and inductively conclude that it’s going to work again in the future.

Since induction is this automatic thing that we do so habitually, it’s legitimate to claim that deduction is this separate faculty like this, I think, rather like how Descartes sees the imagination as sort of separate from the ‘core’ mind, to be studied like a crystal ball.

Then again we don’t treat deductive truths like this at all.