Kant onwards...

According to Kant, Thinking or Thought consists of 3 primary areas:

1. Understanding - It is the source of the faculty of cognition and gives the a priori principles. This is the matter of the Critique of Pure Reason, the last post was the understanding at play. All of Theoretical philosophy falls under the understanding, for through the understanding we have the laws of nature e.g. Newtonian laws of physics (Kant is trying to affirm them in response to the empirical skepticism of Hume)
   
2. Reason - It is the source of the faculty for determination of the particular through the general. This is dealt with in the Critique of Practical Reason, and gives the a priori principles of the laws of freedom (morality). All Practical philosophy falls under Reason. e.g. Reason at work: Is this lie I just said Good?
   
3. Power of Judgment - It is the source of the faculty for the subsumption of the particular under the general and gives the a priori principles for the power of judgment.
   

Now as this whole thing is going to be a build up the the power of judgment I shall explain why Kant added the Critique of Judgment to his other two Critiques in the next post.

This post I hope makes clear the distinction Kant makes with the different faculties we think through.