Between 1937 and 1951 Wittgenstein had numerous philosophical conversations with his student and close friend, Rush Rhees. This article is composed of Rhees’s notes of twenty such conversations — namely, all those which have not yet been published — as well as some supplements from Rhees’s correspondence and miscellaneous notes. The principal value of the notes collected here is that they fill some interesting and important gaps in Wittgenstein ’s corpus. Thus, firstly, the notes touch on a wide range of (...) subjects, a number of which are only briefly addressed by Wittgenstein elsewhere, if at all. The subjects discussed include: explanation, ethics, anarchism, contradiction, psychoanalysis, colour, religion, concepts, classification, seeing-as, evolution, the relation between science and philosophy, and free will, amongst others. Secondly, the notes contain references to, and brief remarks about, philosophers of whom Wittgenstein otherwise says very little, if anything — such as Brentano, Heidegger, Aquinas, and Marx, amongst others. And thirdly, the notes provide us with valuable examples of Wittgenstein ’s use of some key ‘Wittgensteinian’ terms of art which are surprisingly rare in his written works, such as ‘surface-’ and ‘depth-grammar’, and ‘centres of variation’. (shrink)