Er, it was thnidu, not filkerdave, at least I don't see it on any of Dave's userpics and do see it in thnidu's latest post).
I think your "two types" comes back to the difference between belief and knowledge (or at least conviction). If I believe something then I accept that I do not have absolute proof which would convince anyone else (the existence of deity for instance) even though it may convince me. I therefore will not attempt to force other people to agree with me on those subjects, because I know that my evidence is not conclusive for them. If, however, I know that something is true (gravity makes dropped things fall down and hurt my foot) then I will do my best to persuade others of it (otherwise they may drop heavy things on my foot or theirs). I think there is a vast grey area in between as well, where I may try to persuade people but not to the point of forcing them to agree (I may, for instance, try to persuade someone that reading is good, but if they really don't want to read I will give up and leave them to whatever they want to do instead).
And then in the grey area are things which may be believed but which aren't talked about unless someone asks. A lot of the people I know with religious beliefs are like that, if someone asks them they will happily respond, but they don't volunteer the beliefs outside a conversation on the subject.
Definitely there is the third type. There are a lot of subjects on which I have no opinion, or no valid opinion because I am not qualified. (OK, yes, if I researched them then I might have more of a valid opinion, but that is irrelevant because at the moment I do not have one, no matter whether I may have an opinion in the future.) Of course, you are unlikely to hear me talk about them because I have no opinion to express...
no subject
I think your "two types" comes back to the difference between belief and knowledge (or at least conviction). If I believe something then I accept that I do not have absolute proof which would convince anyone else (the existence of deity for instance) even though it may convince me. I therefore will not attempt to force other people to agree with me on those subjects, because I know that my evidence is not conclusive for them. If, however, I know that something is true (gravity makes dropped things fall down and hurt my foot) then I will do my best to persuade others of it (otherwise they may drop heavy things on my foot or theirs). I think there is a vast grey area in between as well, where I may try to persuade people but not to the point of forcing them to agree (I may, for instance, try to persuade someone that reading is good, but if they really don't want to read I will give up and leave them to whatever they want to do instead).
And then in the grey area are things which may be believed but which aren't talked about unless someone asks. A lot of the people I know with religious beliefs are like that, if someone asks them they will happily respond, but they don't volunteer the beliefs outside a conversation on the subject.
Definitely there is the third type. There are a lot of subjects on which I have no opinion, or no valid opinion because I am not qualified. (OK, yes, if I researched them then I might have more of a valid opinion, but that is irrelevant because at the moment I do not have one, no matter whether I may have an opinion in the future.) Of course, you are unlikely to hear me talk about them because I have no opinion to express...