Presumption of naturalism

[robvalue]

I like to pin down definitions because people often don't use a word consistently, and slide it around to fit different parts of an argument. That's a dirty tactic and I like to nip it in the bud. Often people are so used to it they don't realize it, so hopefully I'm doing them a favour if it's unintentional by getting them to think. I found your use of supernatural to be dodgy which is why I pulled it up; similarly I don't think that guy had any idea what he meant by "exist".

Well, truth cannot be known in so far as we can never be sure what we think is true is actually true. That is the problem of solipsism, and also because all information goes through at least one filter first; a filter which cannot be inspected objectively. We can only say something is "true" if it follows logicically from another "true" statement. But sooner or later you need to have axioms/assumptions, or say it's only true insofar as the perceived objective reality exists in some form. Also, we are fallible, so we can never discount simply being mistaken.

Science isn't concerned with absolute truth, it's concerned with models that consistently stand up to scrutiny beyond reasonable doubt.