You can never know the world as it really is — only how it appears to you

In the Critique of Pure Reason (1781), Immanuel Kant argued the mind doesn't passively record reality; it actively structures raw sensation using built-in categories like space, time and causality. What we experience — the 'phenomenal' world — is that processed output, not the 'noumenal' world of things-in-themselves, which Kant said stays permanently out of reach. It reframed centuries of debate over whether we perceive reality directly.

— Immanuel Kant, Critique of Pure Reason — 1781
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