Kant does not refute empiricism - he rescues it. It is Hume that philosophically undermined the standing of empiricism by using its analytical equipment against itself.

First, he showed that causality is logically not possible, all one can maintain is that coincidences happen.

Second, he showed that one cannot draw morals from pure descriptions of man, sociey & nature.

Third, he showed that the self was not unitary, that we, when we look into ourselves are a bundle of sensations.

Kant tackled these criticisms and thus made empiricism possible again. He method was to that mind was always complicit in our understanding of nature, and this not only for science, but also at the preconscious intuitive level.

He said:

Up to now it has been assumed that all our cognition must conform to the objects; but all attempts to find out something about them a priori through concepts that would extend our cognition have, on this presupposition, come to nothing.

This, in summary is empiricism and Humes answer to it. So he goes on to a different tack:

Hence let us once try whether we do not get farther with the problems of metaphysics by assuming that the objects must conform to our cognition

This on the face of it is astonishing. Can, I by thinking, make a chair into a kettle? But this isn't what Kant is saying. He is supposing that our understanding of space & time is already inherent in our own minds - it is that part of our cognition that he calls the intuition, and we impose them onto the world.

One can see from this that he rescues causality - and thus rescues empiricism. He also shows that though we sense only fleeting sensations, and at bottom we are only a bundle of sensations, that bundle, the self also has a reality. He calls this the unity of consciousness. Finally, he founds morality - at least theoretically on a rational principle.

Kant does not refute empiricism - he rescues it. It is Hume that philosophically undermined the standing of empiricism by using its analytical equipment against itself.

First, he showed that causality is logically not possible, all one can maintain is that coincidences happen. Hence empirical physics is not possible.

Second, he showed that one cannot draw morals from pure descriptions of man, sociey & nature. Hence empirical morality is not possible. Traditionally, of course morality had been underpinned by theology.

Third, he showed that the self was not unitary, that we, when we look into ourselves are a bundle of sensations. Thus empirical psychology isn't possible.

Kant tackled these criticisms and thus made empiricism possible again on all three fronts. His method was that mind was always complicit in our understanding of nature, and this not only for science, say when I look at a leaf under a microscope, or even consciously when I just look about my room and nor at the preconscious intuitive level that Freud theorised about; it is at a level so deep within us that they are neccessary for us even to have that thing called experience.

He said:

Up to now it has been assumed that all our cognition must conform to the objects; but all attempts to find out something about them a priori through concepts that would extend our cognition have, on this presupposition, come to nothing.

This, in summary is empiricism and Humes answer to it - '[it has] come to nothing'. So he goes on to a different tack:

Hence let us once try whether we do not get farther with the problems of metaphysics by assuming that the objects must conform to our cognition

This on the face of it is astonishing. Can, I by thinking, make a chair into a kettle? Or turn a man into a moon? But this isn't what Kant is saying. He is supposing that our understanding of space & time is already inherent in our own minds - it is that part of our cognition that he calls the intuition (and not to be confused what we ordinarily call intuition), and we impose them onto the world.

One can see from this that he rescues causality - and thus rescues empiricism. He also shows that though we sense only fleeting sensations, and at bottom we are only a bundle of sensations, that bundle, the self also has a reality. He calls this the unity of consciousness. Finally, he founds morality - at least theoretically on a rational principle.