Science presupposes that observations reflect
an underlying reality.
Not always, and certainly not in some fields! It is not a solid presupposition so much as a working assumption that necessarily guides work. In this way it is a bit like Descartes' notion that some things are simply not able to be doubted if one is to solve any problems.
It presupposes the principle
of cause and effect, and reproducibility of events.
For the former, certainly not in modern physics, which has frequently worked to overturn causality entirely. As for reproducibility, this also breaks down in quantum mechanics, yet you are correct that studies aim for it, as it is impossible to produce a working theory of something if it is a freak anomaly!
All these things SEEM fairly likely, to our common
perception, but none are firmly established, nor has
any axiomatization taken place to give a clear founding
of just WHAT faith science is based upon.
The philosophy of science is filled with arguments like this, though. Frequently what will come out in my expressions are a particular side in that debate, so I freely admit to a certain bias. I'm also a historian of science and not a scientist, so my perspectives and orientation to the field are certainly coloured by a long view, and by a more radical scepticism.
If someone wants an answer to a fundamental question, science is not an appropriate tool, which means that its assumptions are of an entirely different kind from the false dichotomy you have constructed above. The assumptions of science never presume to describe the fundamental nature of the universe, or even to describe anything. Assumptions of that kind have no place in the scientific world.
Actually, they very much DO presume to describe
the nature. They presuppose that it is understandable
through means which are unprovable. THAT assumption
lays a terrible restriction on what is reasonable and not.
See, the problem is that those who have faith in science
simply dismiss all discussions OUTSIDE the realm of scientific
'knowledge', which absolutely prevents them from even seeing
what their faith is built upon.
I can see your point, I think, but I do not agree with the analysis. Science is not about
proving, as answers are both contingent and tentative. It is not a simple matter of scientists missing other solutions because their 'faith' blinds them to it. It actually reflects an intentional limiting of the epistemological playing field, which comes from the desire to locate naturalistic answers which can be studied and (as you note) reproduced (even if only in an equation),
etc. It is a bias created not to blind a discipline, but to
define it; to make it
into a particular kind of discipline and a particular kind of
tool.
And I don't think that scientists all 'dismiss' discussions outside their institutional limitations, but they do dismiss non-scientific approaches from being called science, just as they generally resist making scientific approaches into dogmatic answers to fundamental questions. Science is a way of thinking only, a tool, and not a comprehensive belief system that restricts one from pursuing certain lines of reasoning (no matter what Richard Dawkins says!). There are, you know, plenty of religious scientists, even, and many who argue that science and religion should not overlap at all (cf. Stephen Jay Gould). But unfortunately, many other scientists
do fall into the bad habit of describing their work as reflecting an objective reality which can be understood entirely. This seems to be somewhat an aberration as far as the guiding ethos of both the discipline & world-view goes, at least in my reading of it all.