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Amerindianarts, if you are referring to synthetic a priori knowledge such as mathematical principles, you are absolutely correct — today such principles are continually honed and developed, and work side by side with empirical investigation of the natural world.  Best it should be avoided in the introductory paragraph then.  Pls see my remarks below... 

The distinction between empirical knowledge and a priori knowledge is quite basic and can be found in any of a large number of standard philosophy textbooks.  Nonetheless, if it is to be controversial in this article it whould be avoided in the introductory paragraph of the article, at least until the article is cleaned up and contains reasonable explanations of these various ""empirical"" slants sampled further down in the article. Since this article requires cleanup anyway, I may as well start in bit by bit with some info and references to several such standard textbooks.  To begin, the historical background, if it is to be included at all, is needed going all the way back to the ""debate"" between Plato and Aristotle (yes, innate vs empirical knowledge derived from sense perception.  It is a debate that continues even today, except that in the context of accepted scientific investigation, ""self evident"" (a priori) principles are no longer regarded as acceptable (for at least the past hundred to two hundred years, with the notable exception of what are known as synthetic a priori statements, generally mathematical in nature).  Please be patient with the process, and I will do my best to provide sourcing, at least on this page, and where needed in the article itself as well... "