rationalist and empiricist quotes
Leibniz and Boole illustrate the
Rationalist position where the mind is regarded as an entity that, like a
mathematical system, follows rules that are unique to itself and in a sense independent of the external world. Locke, speaking from the
empiricist position, does not see the mind as independent, but as derivative from the world of experience.
During the first half of the 20th century, the empiricist position dominated the thinking and research on human reasoning in the United States. During the second half of the century, the argument was begun against this position and the rationalist position has achieved increasing dominance. Much of the impetus for the rationalist position has arisen from the mathematics associated with defining and studying computation as well as from the experience of using computation in everyday life.
 Gottfried Wilhelm von Leibniz (16461716), On reasoning. 1677.
 All our reasoning is nothing but the joining and substituting of characters, whether these characters be words or symbols or pictures, ... if we could find characters or signs appropriate for expressing all our thoughts as definitely and as exactly as arithmetic expresses numbers or geometric analysis expresses lines, we could in all subjects in so far as they are amenable to reasoning accomplish what is done in Arithmetic and Geometry.
For all inquiries which depend on reasoning would be performed by the transposition of characters and by a kind of calculus, which would immediately facilitate the discovery of beautiful results ...
 George Boole (1815  1864), An Investigation of the laws of thought. 1854.

The design of the following treatise is to investigate the fundamental laws of those operations of the mind by which reasoning is performed; to give expression to them in the symbolical language of a Calculus, and upon this foundation to establish the science of Logic and construct its method; to make that method itself the basis of a general method for the application of the mathematical doctrine of Probabilities; and, finally, to collect from the various elements of truth brought to view in the course of these inquiries some probable intimations concerning the nature and constitution of the human mind.
 John Locke (16321704) on Empiricism from Essay concerning human understanding. 1690.
 Let us then suppose the mind to be, as we say, white paper, void of all characters, without any ideas; how comes it to be furnished? Whence comes it by that vast store, which the busy and boundless fancy of man has painted on it with an almost endless variety? Whence has it all the materials of reason and knowledge? To this I answer, in one word, from Experience; in that all our knowledge is founded, and from that it ultimately derives itself.
excerpted from web pages of Dr. Schmidt, Rutgers, with permission.