Emil Cioran:
We have convictions only if we have studied nothing thoroughly.
This is true sometimes. And sometimes not. Regarding the natural sciences, having convictions about the physical world around us is rather close to what most of us would call “rational convictions”. Objectivity, in other words. Others can indulge in radical skepticism [re Hume] if they wish but I’m more or less sticking to what the hard guys tell me about gravity and chemical interactions and planetary orbits and meteorological phenomena.
Where convictions start to veer more and more toward conflicting narratives, however, is in regards to damn near everything else. Sure, you can have convictions about moral and political issues, art, religion, what happens after we die etc… And, if you genuinely believe them to be true, then, for you, they are.
But there seems to be no way you can reconfigure your own personal prejudices about things like this so that other rational minds might embrace them so that, in turn, they can be established as the philosophical equivalent of natural laws. And, as Cioran suggests above, the more you peruse things like this, the less your convictions tend to stick around.
Then eventually you wind up with the conviction that one cannot have convictions. Then you think about how contradictory that is. Then you read Wittgenstein. You learn about language. You learn about what language can and cannot be used to express objectively about the world we live in.