CONCEPT
The Illative Sense
Newman's name for the trained faculty of informal reasoning by which a concrete mind reaches certitude in matters that resist formal demonstration — operating below the level of articulable rules, grounded in personal formation.
The illative sense is Newman's technical term for the cognitive power by which a formed mind draws conclusions from the convergence of probabilities in concrete cases. The physician who diagnoses from a constellation of symptoms. The judge who weighs testimony and demeanor. The historian who knows a document is forged. The engineer who feels that something in a system is wrong before she can say what. In each case, the reasoning is rational and the conclusion is grounded — but the grounds cannot be fully articulated, because they reside partly in the reasoner's accumulated history of engagement with the domain. The illative sense is domain-specific, personal, and irreducible to algorithm. It is, in Newman's philosophy, the faculty that makes a person's judgment trustworthy — and the faculty that no machine possesses, because no machine has undergone the formation on which it depends.
In The You On AI Field Guide
Newman developed the illative sense to address what he