This dissertation is an investigation into the relation between mind and language from different perspectives, split up into three interrelated but still, for the most part, self-standing parts. Parts I and II are concerned with the question how thought is affected by language while Part III investigates the scope covered by mind and language respectively. Part I provides a reconstruction of Ludwig Wittgenstein’s famous Private Language Argument in order to apply the rationale behind this line of argument to the relation between mind and language. This argumentative strategy yields the conclusion that reasoning – an important type of thought – is constitutively dependent on language possession and is therefore not available to non-linguisti...