This thesis will explain the fundamental philosophical thoughts of the French philosopher Blaise Pascal. The aim of this paper is to analyze the basic themes found in his philosophical system. The analysis begins with Pascal's distinction between the God of the philosopher and the God of the Christians, and therefore is explained in that chapter his criticism of rationalists and their understanding of God. Furthermore, in the next chapter will be presented, his explicit distinction between the mathematical and intuitive spirit, which are essential in understanding Pascal's interpretation of the human being as a whole. Then the focus will be shifted to Pascal's understanding of human misery and greatness, and it will be explained what human misery consists of, how a person realizes their own misery, the reasons why the individual is in that state and how it can be left. Pascal's understanding of human greatness will be further elaborated, and the connection with human misery will be furthermore explained, also what human greatness consists and what is the connection with the knowledge of God. Finally, the analysis of Pascal's evidence for Christianity, his synthesis of the intuitive and mathematical spirit, and their application in proving Christianity will be presented. In this way, Pascal's complexity in understanding the human being, it’s position in life and his ability to reach knowledge will be fully covered.