Berkeleys idealism has been questioned by many, but it does not seem like anyone has come up with strong, valid arguments which refute his idealist view on knowledge and the world. Can you come up with a demur towards Berkleleys reasoning?
Berkeley certainly didn't prove his metaphysics as being the case anymore than any other such scheme could that. One could either declare it no more special / favored among the pack than any other adequately defended doctrine, or that it was at least unlikely on the basis / bias of whatever rival metaphysics or anti-metaphysical outlook an opponent himself was crouched in.
In light of natural methodology's growing achievements, any metaphysical view, in order to survive, would have had to be made commensurable with the former or to assimilate it without inflicting damage. Somewhat similar to Leibniz's monadology, the natural realm was quite comfortably accommodated for in Berkeley's immaterialism without having to make it transcendent (as say, a classic materialist would do). That is, the regulated perceptions of a human mind conformed to the world which science studies, it was subsumed within those minds (and / or his God) rather the opposite.
Today even brain-centered sciences have to admit what amounts to some brand of indirect realism. That the external environment we experience is produced by our own operating systems (so to speak) from inputted information, rather than being the original source itself. Although one can assert that the simulation is still an accurate representation of some transcendent version of the external world, there are a variety of discoveries in physics which fuels a scientific realism that undermines such a modified clinging to commonsense realism. IOW, that any vestige of this "the immediate external world is within us" theory is so supported also unintentionally assists Berkeley's defense [though the latter holds that only minds / God exist at any metaphysical level].