The Non Self Undermining Constraint

If you have an undefeated reason to think that the compass in your hand is not a reliable compass, it's not a reliable guide to directions, then you're not going to be justified in believing on the basis of this pewative source of evidence. So we're basically running rough shot over the non self undermining constraint here. It's worth considering ways to justify skeptical arguments of a more limited sort by arguing that intuitions of a certain kind are unreliable.