you don’t really have this problem while playing language games in non-philosophical contexts, though. these problems only occur when philosophical language becomes essentialistic and looks behind the use-meaning of a word for some kind of definition that stands in a superfluous relationship to the sense we gather from its use-meaning. here’s an example of what i mean:
in that last paragraph you’re seeing what is meant by the position ‘anti-essentialist’, which allows for different kinds of meaning to be given/found in a variety of language games in which one of these words is used. now check this out; if you found a kantian epistemologist arguing with a humean epistemologist (these two would disagree about the nature of knowledge in many respects), you’d still retain the implicit understanding of the word ‘knowledge’ in its use-meaning despite what either of them said about it philosophically.
you could ask; what are the consequences of being wrong, for both the kantian and the humean, regarding their theory of knowledge. and of course the answer would be; various statements would conflict with other statements in their supporting arguments. but that’s it. still nothing of consequences is observed here. but, what would the consequences of being wrong be like for someone who thought they had knowledge of the right answers, and was wrong? they’d fail the test. or being wrong about the knowledge of how long it would take to get to the airport. they’d miss the plane.
in the former language game, the efficacy of ‘being true or not’ is of no consequence other than perhaps being in violation, or not, of previously accepted rules for the language game being played. you might find a conflict of premises occur between the kantian and the humean - a priori synthetic reasoning is impossible for the humean, and not for the kantian - and insofar as the two agree on the definitions provided in the supporting arguments, they are playing a real language game in which statements can be true or false. but these revolve around abstract and/or essentialistic conceptions of the word in question - ‘knowledge’ - and produce no actual consequences in being incorrect or not.
another problem that becomes increasingly complex in the typical philosophical language game is that for every premise, the number of incidental other meanings that can result becomes incredibly large.
now replace the sentence ‘moses did not exist’ with the sentence ‘experience is subjective’. now this doesn’t mean anything until philosophers get a’hold of it… and watch what happens. that sentence can mean ‘the qualia of experience cannot exist for anyone but the first-person,’ to which the other philosopher replies ‘but if everyone experiences qualia, the fact that qualia is experienced universally makes a certain characteristic of experience objective.’ so which one of these dudes is right?
within the parameters of the philosophical language game, so many tacit understandings are available without any one of them yielding real consequences if they were wrong, that there is nothing against which to test a thesis. on the other hand, ‘moses did not exist’, while being able to mean many things, can be tested in each case. any possible context in which that statement can make sense will reach a terminus… while the making of the sense in the statement ‘experience is subjective’ cannot do so. by the virtue of its essentialistic nature, understanding it would involve an infinite regress of ‘deferral of meaning’, as derrida put it, in an effort to reach a single feature of the meaning that requires no further defining.
and this is only a problem for philosophers who take language out of its use-meaning environment and put it into a game where the rules govern an activity of abstraction… rather than an activity in which a tacit and implicit understanding proceeds directly from a use context.
we’d never need to know if kant or hume were right when we consider whether or not ‘bob knows it will rain’ is true or not. we observe the essence of that ‘knowing’ not in a series of metaphysical statements, but in a series of behaviors that make sense of it; bob doesn’t plan a game of golf, brings the car into the garage, and turns off the water sprinklers, etc.