Godol Hador and DovBear are ripping into each other about their reasons for believing in Matan Torah. GH makes the experiential argument, while DB argues that he's wired to believe in it.
I agree with DB's point (although GH's argument makes sense too). DB's basic point, without all the Hume stuff, is that given his background and upbringing, he believe in Matan Torah. His upbringing created this belief, and he sees no reason to shake it.
In other words, he grants his childhood beliefs a presumption of correctness, which in the absence of compelling evidence to the contrary, requires him to retain that belief.
This argument also works well with belief in G-d. We believe in G-d because we always have. A thinking person's belief system survived to this point, so we presume it's correct. And since the evidence against G-d is less than compelling, we believe.
Certainly the evidence for G-d is nothing more than filling in the gaps. A believer will say that the world is miraculous and therefore could have only been created by G-d. The nonbeliever will give an alternative explanation. But the evidence does not point either way, because it can be read differently by different people.
The presumption breaks the tie in my mind. Like in a trial, where one party bears the burden of persuasion and all the evidence proffered is completely balanced, the jury must return a verdict in favor of the other party, where a presumption exists favoring one side, that side wins if the evidence against it is not compelling.
The presumption doesn't work for certain elements of Judaism. The world being less than 6000 years old is an example. All of the evidence seems to go against this belief. Of course, people can just read the evidence anyway they want (Gosse theory), but that just doesn't seem plausible. Common sense dictates against it. Yes, common sense is not a philosophical tool, but life is too short for philosophical proofs (does anyone seriously consider whether we live in a Matrix unless they make a living off of it?).
I understand that whether an argument is plausible is a question of discretion. Different people will find different arguments plausible. And that's fine. I find the argument that G-d created the world plausible. I don't find the argument that the world is 5676 years old plausible. But that's me.