Depending on your definition of “justified” and “justifiable”, you may run into the problem that eventually your beliefs depend on other believes that depend on other beliefs, and so on until you reach an axiom. And this axiom may be “unjustifiable” or “unjustified”, but you “need” to believe it in order to have any beliefs at all.
One such axiom may be that your brain is “sane”, in the sense that when it tries to use logic to reason about something, you can trust the conclusion. For example, let’s say your thoughts are “All A are B. C is an A. Therefore C is a B.” Can you trust the conclusion that C is a B? Well, maybe you might revisit your thoughts, starting from the first statement “All A are B”. But wait, was that really the first statement? Here you’re relying on your memory, that you can correctly remember what you were thinking about just 2 seconds ago. Is that belief justified? How could you know?
The vast majority of held beliefs are not only wrong and unjustified, but unjustifiable.
If a belief can’t be justified, it shouldn’t be held and it definitely shouldn’t effect your actions.
Depending on your definition of “justified” and “justifiable”, you may run into the problem that eventually your beliefs depend on other believes that depend on other beliefs, and so on until you reach an axiom. And this axiom may be “unjustifiable” or “unjustified”, but you “need” to believe it in order to have any beliefs at all.
One such axiom may be that your brain is “sane”, in the sense that when it tries to use logic to reason about something, you can trust the conclusion. For example, let’s say your thoughts are “All A are B. C is an A. Therefore C is a B.” Can you trust the conclusion that C is a B? Well, maybe you might revisit your thoughts, starting from the first statement “All A are B”. But wait, was that really the first statement? Here you’re relying on your memory, that you can correctly remember what you were thinking about just 2 seconds ago. Is that belief justified? How could you know?
Were you waiting for someone to try correcting “effect” to “affect” so that you could play this trick on them?