Cartesianism was always a subject to Wittgenstein's criticism. In his case against it, he employed a general strategy that I have called "Reductio ad vacuum". There is something right in Cartesianism but without a hidden confusing premise, the truth of Cartesianism is empty. According to the early Wittgenstein, Cartesianism was right be-cause Solipsism is true: the Self is the center of the world. But without confusing this metaphysical Self with the psychological one, Solipsism becomes empty and no different from Realism.