We are the Perfection of Imperfectness The question of the co-existence between rationalism and religion has been argued by many philosophers, such as Descartes. The compatibility between rationalism and religion has brought up many different ideas and thoughts. I do not think that both can be compatible. In English, the word rationalism derives from the Latin word ratio, which means reason. We define rationalism as a system of though that emphasizes the role of reason in obtaining knowledge. When we associate rationalism and religion together we claim that the fundamental principles of religion are self-evident and that revelation is not necessary.