Starting with the analysis of cognitive situations which appear in everyday life, and by means of the logical analysis of some games, the author deals with applied logic in the sense of the general methodology of reasoning. The book acquaints the reader with some forms and operations of reasoning which are applied in the process of scientific cognition as well as in daily activities that require thought. As opposed to a number of well-known and unique handbooks and text-books on pure logic this books conveys learning, and in many cases original thoughts, through witty dialogues, in an entertaining way.