Kant begins his discussion of the understanding by making a number of distinctions between types of logic. The first is between general and special logic. General logic holds for all objects whatsoever, while special logic applies only to objects of a certain type. This means that it contains substantive principles of that science. The next distinction is that between pure and applied general logic.
Applied logic is overtly psychological.
It treats of attention, its impediments and consequences, of the source of error, of the state of doubt, conviction, etc. To some extent, this is reminiscent of an epistemological view known as externalism. According to this view, whether one knows depends on whether one is related properly to the facts to be known. Whereas general logic is not concerned with the origin of our representations, treating all of them alike, transcendental logic would contain rules for a priori thought of objects. According to Kant, some of our cognitions , e.g. space and time, are a priori .