The rationalist
Kant's philosophy is poised in response to popular ideas shared by a school of thought called Rationalism. The rationalist is a person who believes that the world is best treated through black and white analysis. This point of view is shared with Empiricism, except that Empiricism places the focus on direct observation, whereas Rationalism prioritizes the human mind and its ability to calculate. In any case, Kant rejects this point of view, observing that there are inherent flaws in the worldview.
The moralist
Kant's rejection of Rationalism doesn't make him a moralist either. In fact, he takes the Moralistic side of the equation to task as well. Whereas the rationalist finds meaning in the human calculations about the world, the moralist does the opposite, finding meaning primarily in the human capacity for good and evil. Kant observes that there are blatant problems with Moralism as a metaphysic, because Moralism seems to stem from emotion and circumstance.
The human being
The answer to Kant's quest for an all-encompassing theory of reality leads him to considering the abilities of a human being. Instead of seeing the world through either the cosmic-centered Moralism of religion or the black and white mathematics of Rationalism, he draws an obvious conclusion about the human being and works from there: Humans both know things and don't know things, and they don't know what they don't know. In other words, a human is a finite being, so they cannot do philosophy about all knowledge, because there is obviously more to reality than can be observed; this does not make his philosophy religious, he maintains, because it is simply true that humans cannot know what their minds and bodies do not perceive directly. He synthesizes the approaches and reconciles them.