This chapter presents an interpretation of the first twenty or so sections of the Philosophical Investigations. For Wittgenstein, meaningful language is ultimately a kind of human action, indeed the characteristic kind of human action. This chapter compares and contrasts Wittgenstein's philosophical intentions in the Philosophical Investigations with his intentions in the earlier TractatusLogico-Philosophicus. It then explicates the meaning-is-use thesis, unpacking Wittgenstein's opening argument for the meaning-is-use thesis. It concludes, on Wittgenstein's behalf, that the thesis that meaning-is-use is the best overall explanation of all the relevant meaning-facts or meaning-phenomena. From Steps A, B and C presented in the chapter, it follows that the meaning-is-use thesis is true, including the important qualification that sometimes the human act of ostending an object that bears a name also explains the meaning of that name. In this way, the Augustinian theory of language leads directly from Referentialism to human action.