Rationalism is a term derived from the Latin word ‘ratio’ which means reason. Rationalism is a view or thought which appeals to reason as a principal source of attaining knowledge and justification of things. Technically, rationalism is a method in which the reason that is supported by observation, should serve in an excellent way, as the source of all our convictions. Since there are various degrees of emphasis in this method, it leads to a wide range of rationalist viewpoints from a moderate view or position which justifies, “The Reason has the high priority to obtain knowledge over other ways” to an extreme view or position which justifies “Reason is the only approach to knowledge”.

If we analyze the background of rationalism, it’s related with the introduction of the mathematical techniques into philosophy, which is called as continental rationalism. Empiricism, which is contrasted with rationalism, is the theory of knowledge in Philosophy that emphasizes the role of evidence that arises from knowledge, is gathered through experience. In the Philosophy of Science, Empiricism emphasizes that the scientific knowledge and its aspects are associated with evidence and they are discovered through experiments. But the difference between rationalism and empiricism was drawn at a later stage.

Socrates, one of the Founders of the Classic Western Philosophy, was a Greek Athenian Philosopher. He believed that humans need to understand themselves before they understand the world. According to Philosophy, Man is made up of two parts, a soul and a body. The soul has its two parts namely Rational and Irrational. Rational part is our true personality. Irrational part refers to our desires and the emotions or feelings. In a human being’s life, the irrational soul is inside the physical body and it is bonded with the desires and emotions. The rational soul is beyond the knowledge of conscience. Rationalism is to purify and extract the irrational source from its bondage from the human’s physical body and connect it with the rational soul through a moral growth which makes a complete man. The rational soul recognizes the world in a spiritual aspect or view. To know this world, one should know or understand oneself as soul.

Rene Descartes, French Philosopher emphasized that the knowledge of all truths of the aspects such as mathematical methods, epistemological and science, could be reached only by Reason. The Dutch Philosopher Baruch Spinoza developed a Systematic and Logical approach of Rational Philosophy and he proposed in all his ideas that God exists in this world, only through philosophy. Immanuel Kant, who is a traditional rationalist, developed an influential rationalism, which synthesized the traditional rationalist and the modern empiricist traditions. All these philosophers shared the common belief that the world is best understood through logical thinking and reasoning ability. However, they were also believers in science and experiment.

It is through these rationalists we know many facts about the world we live in. Their logical thinking and reasoning has brought forth many facts which remained contradictory to the beliefs that existed for centuries.