UNIT 12

Rationalism and Empiricism

Rationalism is a view emphasizing the role or importance of human reason. Rationalism starts from premises that cannot coherently be denied, then attempts by logical steps to deduce every possible object of knowledge.

The first rationalist is often held to be Parmenides, who argued that it is impossible to doubt that thinking actually occurs. But thinking must have an object; therefore something beyond thinking really exists. Parmenides deduced that what really exists must have certain properties. Zeno of Elea was a disciple of Parmenides, and argued against the reality of multiplicity and that motion is impossible. Plato was also influenced by Parmenides, but combined rationalism with a form of realism. The nature of a man, a triangle, a tree, applies to all men, all triangles, and all trees. Plato argued that these essences are mind-independent ‘forms' that humans (but particularly philosophers) can come to know by reason, and by ignoring the distractions of sense-perception.

Modern rationalism begins with Descartes. Reflection on the nature of perceptual experience, as well as scientific discoveries in physiology and optics, led Descartes (and also Locke) to the view that we are directly aware of ideas, rather than objects. He began, echoing Parmenides, with a principle that he thought could not coherently be denied: I think, therefore I am (often given in his original Latin: Cogito ergo sum). From this principle, Descartes went on to construct a complete system of knowledge (which involves proving the existence of God, using, among other means, a version of the ontological argument). His view strongly influenced those philosophers usually considered modern rationalists such as Baruch Spinoza, Gottfried Leibniz, and Christian Wolff.

Empiricism is the belief that all knowledge comes from experience. The "empirical world" is the world of the senses, i.e. the world we can see, feel, touch, hear and smell. Empiricism, in contrast to rationalism, downplays or dismisses the ability of reason alone to yield knowledge of the world, preferring to base any knowledge we have on our senses. John Locke propounded the classic empiricist view in An Essay Concerning Human Understanding in 1689, developing a form of naturalism and empiricism on roughly scientific (and Newtonian) principles. John Locke thought that the human mind at birth was a tabula rasa on which experience writes the general principles and details of all knowledge. This is completely opposite to the rationalists. Whereas a rationalist would attempt to find knowledge by thought alone, an empiricist would use the methods of the experimental sciences.

Ex. 9 Write questions to the following answers.