For Descartes, the individual is capable of thinking beyond the physical and real, and this can be done by arguing based on pure reason. His version of "truths" about human existence and other universal truths about life can be generated from human reason alone, in the same manner in which he proved his existence as a result of his belief that he is "persuaded" that he exists. That is, even though experience and reality does not provide proof of his existence, the fact that Descartes believed that he existed is proof enough that he, indeed, exists in the world he lives in. Descartes' questioning of reality and experience profoundly helped the manner by which human knowledge is created and developed. Rationalism as a philosophy puts premium on the human ability to think and reason, and through these attributes, be able to create ideas that make sense of one's existence and experiences in this world. For the rationalist such as Descartes, knowledge need not be established as "truths" based on physical manifestations or experiences; it is enough that the individual believes this 'truth' to be so, as long as the arguments and line of thinking presented are consistent and valid.

Du Bois, meanwhile, promoted the philosophy of empiricism because it is through this philosophy that he and his Negro community were able to make sense of their reality as a discriminated and prejudiced sector in American society. While Descartes' philosophy puts premium on the human ability to think and reason for himself, and ultimately, come up and develop universal truths about life and knowledge, Du Bois puts primary importance on collective experience as the 'key' to understand the Negros' realities and experiences of oppression from the dominantly white American society.

In "Souls," Du Bois argued how Negro slavery and oppression is just...

In Chapter 1 of "Souls," he described, in experiential dimension, the oppression of the Negros in every facet of their lives and existence:
He began to have a dim feeling that, to attain his place in the world, he must be himself, and not another. For the first time he sought to analyze the burden he bore upon his back, that dead-weight of social degradation partially masked behind a half-named Negro problem. He felt his poverty; without a cent, without a home, without land, tools, or savings, he had entered into competition with rich, landed, skilled neighbors. To be a poor man is hard, but to be a poor race in a land of dollars is the very bottom of hardships. He felt the weight of his ignorance, -- not simply of letters, but of life, of business, of the humanities...The red stain of bastardy, which two centuries of systematic legal defilement of Negro women had stamped upon his race

Descartes, R. "Meditations." Available at http://www.ship.edu/~cgboeree/descartesmeditations.html.

Du Bois, W.E.B. "Souls of the Black Folk." Available at http://www.bartleby.com/114/1.html.