Foundationalism holds that all beliefs must be justified in order to be believed. Beliefs, therefore, fall into two categories:
- Beliefs that are properly basic, in that they do not depend upon justification of other beliefs, but on something outside the realm of belief (a "non-doxastic justification")
- Beliefs that derive from one or more basic beliefs, and therefore depend on the basic beliefs for their validity (link)
Sounds simple, doesn't it? Unfortunately, many religious try to justify their beliefs as foundational, thus, not requiring the need for evidence. This can be seen at its extreme within the Reformed Epistemology movement. As far as I can determine, there are few beliefs that qualify as foundational. I think of mathematics and logic as qualifying. Can you think of others? How about Core Values? Hey, how about science: "- - - (science) is validated by its results and needs no a priori justification."
Oh, remember: "science" means "knowledge" in Latin and "knowledge" philosophically means "True, Justified Belief." It is the ONLY epistemological system that verifies/justifies its beliefs.