Full Idea
In Kantian idealism, the objects conform to the understanding, and not the understanding to the objects.
Gist of Idea
In Kantian idealism, objects fit understanding, not vice versa
Source
report of Immanuel Kant (Critique of Pure Reason [1781]) by Ludwig Feuerbach - Principles of Philosophy of the Future §17
Book Reference
Feuerbach,Ludwig: 'Principles of the Philosophy of the Future', ed/tr. Vogel,M [Hackett 1986], p.28
A Reaction
This labels Kant as an idealist, but he was also a realist (of a very minimal sort). Modern cognitive science shows clearly that Kant is at least partially correct. Personally I think I see squares as square because they are square.