The thing is, it’s not even really about whether you can defend it to others. It’s whether you can defend it to yourself. That’s intellectual honesty. If all one does is listen to people they agree with, and read arguments that re-inforce their belief, and block out countervailing viewpoints, I think that’s tantamount to lying to one’s self.
Discussion
It depends on the subject. Are we talking about things like crypto projects or are we talking about “how do you know good thing is good” type of stuff?
With the latter, knowing is different from showing.
I like Common Sense Realism https://en.m.wikipedia.org/wiki/Scottish_common_sense_realism
Well, I subscribe to Hume's moral skepticism, and I am not generally a fan, like Hume, of a priori reasoning at all. So I think the view generally can apply to everything.
Obviously, I'm not interested in debating whether the sky is blue. But when it comes to ideology, politics, culture and ethics ... I take nothing for granted in these domains.
I think this kind of “evidence based virtue” is how you end up with a whole host of heinous ideas. Just look how the 20th century french philosophers ended up haha