The following three propositions constitute an inconsistent triad:
1. Foundationalism: All knowledge and justified belief rest ultimately on a foundation of noninferential knowledge or justified belief
2. Knowledge Account: All justified beliefs constitute knowledge.
3. Knowledge from Falsehood: It is possible to derive knowledge from falsehood via inference.
In support of (3), consider:
Cooper’s parents tell him that Santa is going to leave presents under the tree and he believes he will have presents because he believes Santa is bringing them. We can rightly say he knows he will have presents even if we stipulate that given his background beliefs he would only believe he will have presents if he believed Santa was going to bring them.
We should give up Foundationalism.
There you go. The argument with very limited appeal!
Myself, I'd reject the knowledge account, but since I think that there are no false, justified beliefs and think that knowledge entails justification, I'd have to say that some justified beliefs rest on a foundation of unjustified beliefs. Or, something like that.