If by "theory of knowledge", you mean they need to have read a bunch of philosophical musings on epistemology, then I strongly agree with the downvoters, because that's utter nonsense. If you mean anything else by that, then you're being way too vague to contribute to a technical discussion, so again I agree with the downvoters. Try defining what you mean by "theory of knowledge" and explain why you think that's required to "understand science" (and you might want to explain what you mean by that too) and I suspect you'll see a lot fewer downvotes.