| There is nothing I'm aware of in epistemology or the philosophy of science that says that nothing can be completely true -- if you know of something specific, let me know. What it does say is that we can never be certain of any knowledge. It's not that nothing can be completely true; it's that we can't be absolutely certain that something is true. It may sound like a subtle difference, but it's quite an important one.
Science is a progressive metholodogy for acquiring and refining knowledge. It makes a bunch of assumptions (assuming material reality is one of the most important) that it cannot prove, but this doesn't make it partially false. Incomplete, maybe; but not partially false. The method of science is intended to overcome the fallabilities of both the men and women 'doing' science and the limits of logic and knowledge. It may not do this perfectly (some argue it does; I think they're wrong), but it does make significant efforts in that direction.
The most common model of science used is generally based on Popper. His articulation of logical positivism centres on falsification. We come up with a hypothesis (which should be loigcally derived), then look for information that will disprove the hypothesis. If we find no disproving evidence, then we (tentatively) support the hypothesis. If there is disproving evidence then we reject the hypothsis. There is no notion of positive evidence to prove a hypothesis -- largely a legacy of Hume's skepticism. It might be accurate to say that no scientific hypothesis can be guaranteed to be true, nowhere does it imply that the hypothesis can be 'partially' true. A hypothesis is true or false.
Now, some theories have such a huge body of evidence (non-falsified hypotheses) that it is generally considered that they are correct. This doesn't mean that we are 100% certain of it -- but that we think it is extremely unlikely that the theory is false (gravity, for example). This does not mean that gravity is partially true. It might mean that gravity is a partial or incomplete explanation of what is going on. But this doesn't make it 'half true'.
From what you've written, if you replaced the term 'untrue' with 'uncertain' then I'd probably come pretty close to agreeing with you. But I would still be left asking myself, "and so...?" |