The text below is divided into four sections. The first section deals with the concept of ‘critical thinking’. What exactly is critical thinking? What are the characteristics of the critical thinker? Section two focuses on the question how critical thinking can be mastered.

The answer to this question follows logically from the six key lessons as formulated by Van Gelder. One of the key lessons is the importance of visualizing reasoning by means of argument maps. The third section responds to the question of what argument mapping actually is, and briefly deals with the history and use of argument mapping. Finally, the last section is about Rationale, a program for argument mapping.