With characteristic candour, David Hume is prepared to admit that in ordinary life, but certainly not when reflecting on the nature of perceptual experience, he has no option but to ‘believe in the existence of body’ despite his philosophical reasonings to the contrary. In this instance, his commitment to ‘Common Sense’ has become, as it was not to become for his contemporary Thomas Reid, a direct consequence of participating in a day-to-day existence if nevertheless one which he has no option but to reject when reflecting in the study. Ludwig Wittgenstein, on the other hand, presents us with a picture of what has come to be regarded as a form of Humean ‘phenomenalist language’, private in nature, which, in one of the most famous passages of his later philosophy, he appears to reject via a form of reductio ad absurdum argument. In what follows, it will be questioned whether his ‘argument’ clearly represents phenomenalist proposals which Hume’s successors, e. g., A.J. Ayer, accepted without question. If there is a misunderstanding here on both sides, an investigation into its nature must lead to an appreciation of the varying roles attributed by these philosophers to the notion of ‘Common Sense’.