What is Immanuel Kant reaction on pure reason?

Immanuel Kant believed that pure reason is limited in its ability to understand and know the world, as it is bound by the constraints of human cognition. He argued that pure reason alone cannot access fundamental truths about reality, and that a combination of reason and empirical observation is necessary for true understanding. This led Kant to develop his theory of transcendentally ideal knowledge, where knowledge is structured by the mind rather than being a direct representation of the world.