The word 'believe' has no place in a scientific debate. Either you know or you don't know. What you believe does not enter into it, that means you need to do more research or read up on the research that has already been done.
That's nonsense. There are lots of parts of science where someone could reasonably say "I believe it's this, but I'll change my mind if future science changes my mind".
An example of where this is useful is around Neanderthals. "Did they have language?", "Did they have burial with ceremony?" are questions where it's fine to have belief on the current evidence because there's not enough data to know the answer.
This is incorrect. There are many scientific hypotheses that are widely believed to be true, such as P!=NP or global warming. To say that "we don't know", or "it's equally probable that..." would be extremely misleading. And you'd be hard pressed to find a scientist who doesn't believe in one outcome or the other.
