James Van Cleve in "Foundationalism, Epistemic Principles, and the Cartesian Circle" is both a knowledge problem and a theological problem, which might lead to skepticism if you wanted to take it down that road. Here are the premises that Cleve gives:
(1) I can know (be certain) that (p) whatever I perceive clearly and distinctly is true only if I first know (am certain) that (q) God exists and is not a deceiver.Put another way, (1) having a sound belief system depends on knowing that a non-deceiving God exists, but it also seems, to Descartes, that (2) knowing that a non-deceive God exists depends on having a sound belief system.
(2) I can know (be certain) that (q) God exists and is not a deceiver only if I first know (am certain) that (p) whatever I perceive clearly and distinctly is true.
The problem Laurence BonJour addresses in "Can Empirical Knowledge Have a Foundation?" is ultimately a skeptical problem, too, one that creates a kind of regress. I'll lay the argument out like this, even though he doesn't.
(1) For any of my beliefs, I must have good reasons for my beliefs.It's like this: You have to have good reasons for your beliefs but then you have to have good reasons for those reasons and good reasons for those reasons and good reasons for those reasons and so on. That seems to be the problem.
(2) Reasons are beliefs.
(3) For any of those good reasons, I must have good reasons for those reasons ad infinitum.
So, (4) there must be an infinite set of beliefs for any beliefs that I have.
So, (5) foundationalism is false and coherentism is false by definition.
Ernest Sosa's "Reflective Knowledge in the Best Circles" is an appeal to other things besides truth and coherence to account for knowledge. He writes:
Knowledge requires truth and coherence, true enough, but it often requires more: for example, that one be adequately related, causally or counterfactually, to the objects of one's knowledge, which is not necessarily ensured by the mere truth-cum-coherence of one's beliefs, no matter how comprehensive the coherence. Madmen can be richly, brilliantly coherent; not just imaginary madmen, but real ones, some of the locked up in asylums. Knowledge require not only internal justification or coherence or rationality, but also external warrant or aptness. We must be both in good internal order and in appropriate relation to the external world.So I didn't examine Van Cleve's or BonJour's arguments against these ideas, and I didn't examine the way in which Sosa arrives at his conclusion really. But maybe I will talk about some of these things in the next post.