How honest should you be with yourself? Three questions:
Question 1: What do you know?
There is a difference between what you believe and what you know. You probably believe a bunch of things which you don’t know (as I do, unavoidably). What follows from this? Are you ever justified in acting like you know a belief is false, if you categorically can not know it (Do unicorns exist? Will the sun rise tomorrow?)? If you are justified in dismissing specific beliefs, where is the line drawn?
Question 2: When should you be uncertain?
If you decide to act as if you know a belief is false, might it actually be true? What could follow from this? If the act of dismissal means you are never open to a given truth, are those stakes too high to dismiss anything? Perhaps a genuine uncertainty of all beliefs is warranted, with a genuine open-mindedness to literally every belief, as long as we can not logically know it is false. If you do this, does this prevent you from acting on anything? For example, if you don’t know that a chair exists, but you just believe it and act accordingly, is that justified? Or, should you participate in the active doubting of chairs?
Question 3: Should you be confident in your beliefs?
If you dismiss a belief (that unicorns exist under Antarctica), are you justified in being confident of this? Should one ever ridicule the beliefs of someone else, if they can not know with certainty that those beliefs are false? If not, does that mean you need to have intellectual respect for someone who believes that invisible, unmeasurable Hot-Pocket-regurgitating piglets live in the center of Mars? Should one really approach such a belief with humility?
Are you certain?
Here’s my take on it: you don’t have to take a stand either way if your focus is on what you can know, not what you can believe. There is so much relevant, practical information that you can know with certainty, and instead of dealing with uncertain beliefs, stick to knowledge. That way, you can have a genuine intellectual humility when it comes to all beliefs, as long as it does not cross into the realm of knowledge, where you can logically eviscerate it.