Certainty in Action is an invaluable collection of Danièle Moyal-Sharrock’s papers appeared after her seminal Understanding Wittgenstein’s On Certainty (2004). It focuses on the centrality of action and claims that this is the distinctive trait of “the third Wittgenstein” – the one that, after the Wittgenstein of the Tractatus and the one of the Philosophical Investigations, wrote the Remarks on the Philosophy of Psychology, the Remarks on Colour and On Certainty.