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How did Kant’s ideas change the traditional contrast between mind and world?

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Fragment of a Roman fresco showing Socrates seated and draped in a white robe, with Greek text above, on a red background with visible cracks. — Philosophical anthropology Socrates, Roman fresco, 1st century bce; in the Ephesus Museum, Selçuk, Turkey.

Immanuel Kant fundamentally inverted the traditional epistemological relationship between the mind and the world, a shift he famously compared to the Copernican revolution in astronomy.12

Prior to Kant, knowledge was generally understood as the mind accommodating itself to an external world. Kant argued instead that the world must conform to the requirements of human sensibility and rationality. Under his doctrine of transcendental idealism, human knowledge is a synthesis of sensory data and the mind's own contributions. The mind imposes specific structures—such as the forms of space and time and various categories of understanding—onto experience to make it intelligible.12

Consequently, humans can only know phenomena, or things as they appear through these mental filters. While Kant maintained that a mind-independent reality exists—the noumena or "things-in-themselves"—he asserted that this realm is fundamentally unknowable because it exists outside the necessary conditions of human perception and causal relations.321