René Descartes is one the great philosophers and scientists whose thoughts and works influenced the development of the modern philosophy. He is also known for his Cartesian coordinate system in Mathematics. He was, in the full sense of the word, a partaker of the modern spirit and the first of the modern school of mathematicians. What is the influence of his work on the scientific thoughts up to nowadays? This is the story of René Descartes, the founder of the modern philosophy, the father of the method of reasoning.