This thesis aims to evaluate Ludwig Wittgenstein's treatment of the traditional skeptical problem of the existence of the external world. It is especially in On Certainty where we find relevant thoughts on the topic, such as discussions about the meaning of skeptical doubt and about knowledge claims. Wittgenstein essentially rejects the problem. Against skepticism, Wittgenstein maintains that our basic certainties are outside the scope of doubt and are also a condition for the possibility of any language game (including that of doubt). Against Moore and the philosophical tradition in general, he intends to show not only that it is meaningless to give a response to the false problem of the external world, but also to associate our basic certainties with an epistemic vocabulary. My goal is to point out problems in Wittgenstein's criticisms. I first present a strong version of skepticism about the external world, and then show that his criticisms only work against a weaker version of skepticism. As for his attacks against Moore, I argue that they only work at the high cost of inconsistency with his own metaphilosophical views. The conclusion that I want to reach is that the problem of the external world remains alive, despite Wittgenstein's attempts to reject it.
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