thiruchitrambalam, Empiricism, rationalism and transcendental idealism:
There has been two major schools in philosophy which have been having opposing views on the fundamental principle in metaphysics.. they have been dominating the medieval europe for more than three decades . they are empiricism and rationalism. The empiricists think that the knowledge is a product of the inputs from the perceptual organs like eye,ear,nose ,tactileand taste. The perceptions leads to the knowledge of the universe. Hence they think the experience lead to the knowledge of the universe. The rationalists however feel that the ideas or thoughts come first. Because we name the objects as such and such they become to be known so. In their view the mind is not a clean slate and the thoughts are already there to guide it. That is in essence the thoughts are primary and perceptions are secondary.
The empiricists were BERKLEY,LOCKEY AND HUME. The famous rationalists wereDECARTES,ESPINOZA AND LEIBNEITZ. Decartes famous statement" cogito ergo sum" Iam thinking therefore Iam .was instrumental in huge development of logic,scientific discoveries and industrial revolution. In the middle of the 18th century an important turn took place in the empiricism-rationalism dichotomy. This is brought about by IMMANUEL KANT. He was born in Konigsberg in present day germany. He proposed that the brain has the innate capacity to take both thoughts and perceptions and to evaluate them and process them to information and knowledge. This has brought in what is known as the COPERNICAN REVOLUTION in philosophy. This is called TRANSCENDENTAL IDEALISM which gave new dimensions in the growth of epistemology,phenomenology,existentialism and psycho-analysis. Saiva siddhantham is one of the earliest schools in india to embrace existentialism and phenomenology.In fact almost most of the hindu-buddhist schools have substantial body of phenomenology and existentialism in their thought. Terms like aham brahmasmi, thathvamasi .pazham nee etc have existentialistic connotations. The siva gana bodham verses four and five have dwelved on thes basic issues of empiricism and rationalism and their irrelevance. The Kantian revolution has been made well in 13th century itself in SGB.