@Ding an Sich,
Ding_an_Sich;152214 wrote:What I would like to get at is when it is appropriate to say these things (belieing, knowing, and certainty) as well as whether certain words function the same as others e.g. belief and opinion, believing and knowing, etc. Witt probably has cleaned most of this up, but that doesnt mean we shouldnt further investigate.
1.We believe when we accept a proposition as true.
2.We know when we have a belief that is both true and justified.
3.We are certain when it is impossible for us to be mistaken
4."Belief" and "opinion" are closely related, but "opinion" is often used to mean, "a matter of opinion" when "matter of opinion" means that there is really no truth or falsity involved. For example, "It is a matter of opinion whether vanilla ice-cream tastes better than chocolate ice-cream". That means that, as the logician Quine put it, "
there is no fact about the matter" It is neither true nor false.
5.Finally, we can believe when we have no justification for our belief, and our belief is not true. Which is to say, belief does not imply justification, nor does it imply truth. On the other hand, knowledge implies both justification and truth. We cannot know unless we have justification, and what we claim to know is true. So there is a great deal of difference between belief and knowledge
So now you have answers to the questions that bother you.
Of course, the fact that people in ordinary conversation sometimes confuse these terms has no more significance than the fact that sometimes in ordinary conversation, people confuse other terms. But, more important is that it is not the terms that are important, but the
concepts these terms are about. So, when people confuse these terms, that is a trivial matter, and does not affect the concepts. In English, for instance, people often confuse the terms, "uninterested" and "disinterested". But, so what? The two concepts these terms are about are quite different. That people confuse them is a socio-linguistic fact. It has no significance philosophically.