Speaking of innate and universal "truths," Locke argues: "If therefore children and idiots have souls, have minds, with those impressions upon them, they must unavoidably perceive them, and necessarily know and assent to these truths; which, since they do not, it is evident that there are no such impressions" (Locke). Finally, Locke claims that the "blank slate" of an infant's mind, also called the "tabula rasa," offers proof that innate knowledge does not exist. As he points out, there is great variation between the painted canvasses of men's minds, all depending upon what the individual experiences, reflects upon, and chooses to give his attention to after birth (Locke). If Descartes' theory about innate knowledge is true, all men would share the same set of ideas. However, as Locke points out: "Men then come to be furnished with fewer or more simple ideas from without, according as the objects they converse with afford greater or less variety; and from the operations of their minds within, according as they more...

These arguments are centered around three basic concepts: universal assent and the lack of proof that this universal knowledge cannot be gleaned after birth, the fact that children and the mentally disabled do not share in universal knowledge, and the tabula rasa, or blank slate of a newborn's mind, that leads to significant variation among men in terms of beliefs and principles (Locke). In complete opposition, while Descartes was distrustful of man's ability to learn valuable lessons from his sensory experiences (Descartes), Locke believed empirical learning is the path to universal truth and understanding.
Works Cited

Descartes, Rene. "Meditations on First Philosophy." 2001. classicallibrary.org. 12. 02-2011 .

Locke, John. An Essay Concerning Human Understanding 38 E. Essay. London: William Tegg, 1689.