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Articles

One Law to Rule Them All

Tim Wilkinson tries to chart our quest for consistency without contradicting himself.

Consistency doesn’t guarantee truth, but as ancient Indian and Greek philosophers realised, it helps. Socrates, both in person and in his incarnation as the main character in many of Plato’s dialogues, was famous for his trademark method of posing questions to his interlocutors in order to tease out contradictions in their thinking; but it was in one of Plato’s students – Aristotle – that consistency found its champion.

Aristotle & Barbara

Aristotle (384-322 BC) identified a number of rules of reasoning he termed syllogisms, which were later given charming names by medieval philosophers. It would take too long to describe them all, but here’s an example called Barbara:

Premise 1: All mammals are vertebrates.

Premise 2: All cats are mammals.

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