Programs with Common Sense
McCarthy proposed a system given knowledge as sentences of formal logic, where new behaviour comes from new sentences rather than new code.
Why it matters
Separating knowledge from the inference mechanism became the basis of every later rule-based system.
McCarthy called the hypothetical system an advice taker: you advise it rather than reprogram it. It was never fully built, but the framing led to logic programming, to expert systems, and to a long argument over whether common sense can be written down as sentences.