<logic, epistemology> Kant believed that when reason goes beyond possible experience it often falls into various antinomies, or equally rational but contradictory views. Reason cannot here play the role of establishing rational truths because it goes beyond possible experience and becomes transcendent. E.g. Kant thought that one could reason from the assumption that the world had a beginning in time to the conclusion that it did not, and vice versa. This was part of Kant's critical program of determining limits to science and philosophical inquiry.
[A Philosophical Glossary]
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