Kant found four questions where the answer and its exact opposite both seem provable

Does the universe have a beginning in time, or has it always existed? Is matter infinitely divisible, or built from indivisible parts? Kant showed reason can construct an equally rigorous-looking proof for both sides of each question, and argued the contradiction reveals reason overreaching what it can actually know.

— Immanuel Kant, Critique of Pure Reason — Transcendental Dialectic, 1781
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