Often in Philosophy, something quite simple is missed and that is, few stop to think about when they are in fact presupposing.
For instance, most people think that in order for beliefs to be justified, we must have reasons for a belief. However, beliefs simply come to be and aren’t invented and can’t be chosen. In that case, not all beliefs can be justified via “reason to assert” and not all warranted beliefs require justification; entitlements, for example.
But the main problem is that people fixate on the idea that justification puts onus on the believer rather than on the interlocutor. So when a person insists some x, y, and z isn’t justified until there’s an explanation, the response should simply be that such an x, y, z belief exists, and what positive reasons are there to doubt it?
In other words, genuine beliefs can already be seen as justified, and doubting them or questioning their validity puts onus on the examiner, not the one being examined.
That means that the fitness of a belief isn’t in any essential way, tied to justification, but tied to, well, fitness! Is a belief sustaining its application? In that sense of justification, then the foundation of belief is ordinary experience, not supposition nor justification. It’s the application of an idea and its fitness for that application which warrants belief.
In “The cat is on the mat”, justification doesn’t hinge on infinite regresses of propositions that must be proven before a conclusion can be reached. Simply, when there appears to be a cat on the mat, the only sensible question that must be justified is “Why should I doubt the cat, the mat, or that the cat is on it?”
“Because you may be wrong” or “Because you can’t be certain” isn’t here or there because absolutely no conditions exist in which we can be absolutely certain of anything and for the fact that nothing ensures we will conclude rightly or wrongly, and that the former is only a matter of Psychology, and the latter, a fact of human inquiry and knowledge.
Why should I believe? No, why should I doubt?
Just a thought.