The Question of the Source of Knowledge

Emmanuel Kant in his metaphysics tried to put forward a method that would undermine the rationalistic metaphysics. He doubted the presupposition that reality can be understood by way of concepts. This was a response to the unpopularity of metaphysics among science minded thinkers of the modern era as well as the destructive criticisms leveled against metaphysics by the British empiricists. It was Hume’s criticisms that occasioned Kant’s critique. The thoughts of some thinkers contributed in shaping Kant’s critical mind. Descartes philosophy influenced Kant‘s general philosophical outlook. Descartes was a rationalist. In his discourse on method he situated epistemology before metaphysics. For him the reality of the external world and of God is only provable from the certainty of the existence of the ego. Kant on the other hand makes the analysis and criticism of the human reason the work of real metaphysics. Descartes’ theory of ego influenced Kant so much so that he attributed the unity of appreciation to the ego. Descartes’ dualism of “res cogitans” and “res extensa” also influenced Kant’s idea of the noumena and phenomena. Descartes argues that reason is the only authentic source of knowledge and that it is innate. However, Kant argues that both reason and experience contribute to knowledge. While Descartes proves the existence of God by way of the idea of God, Kant objects it saying that God’s existence and his nature cannot be reasonably asserted.

Another philosopher that influenced Kant is Locke. Locke disagrees with Descartes’ theory of innate idea saying that the mind prior to experience is a “tabula rasa”. He introduced the theory of noumena and real presence. However Kant rebutted the tabular rasa theory.

Berkley philosophy equally influence Kant‘s reasoning. Berkley’s idea that reality is all about that which is perceptible exerted much influence on Kant such that Kant limited the scope of human knowledge to what is perceptible and as such metaphysics is ipso facto an impossible science.

Hume’s criticisms extend to all spheres of human knowledge. His criticisms of mathematics, physics and metaphysics moved Kant to question the basis of these presumed sciences. This is based on his denial of causality as an apriori concept. He intensely questions the ontological status of substance, the mind, the soul, happiness, freedom, time and space, and God. In his view the notion of cause and effect is possible by reason a priori but it arises from experience. It is false idea to believe that because something has always happened in the past that it would always happen in the future. There is no necessary connection between two events or objects which we call cause and effect. It is only a succession of different events. Hume does not believe that the notion of course possesses an a priori character. Kant was not at home with that view to the extent that he went ahead to redress the basis of mathematics and science and to ascertain whether metaphysics could be done scientifically.

Kant’s immediate predecessors agree that the problem of knowledge is the major problem of philosophy. Rationalism is the view that the true source of knowledge is reason while the empiricists hold that knowledge comes from the senses. Kant’s critique of pure reason was reconciliation between rationalism and empiricism.

By this Kant mean to say that like Copernicus who changed people’s understanding on the relationship between the sun and the earth, he is also changing people’s idea of the relationship between the knower and the known. Before Kant’s epistemology, it was believed that the external object impresses itself on the senses which in turn, affect the mind. However, Kant argues that the mind acts on the external world, forcing it to adopt the mind’s pre-conditional modes. In this connection therefore, both reason and experience are essential sources of the human knowledge.