This thesis develops an account of ethics called the Linguistic Perspective, which is realist in a practical, non-theoretical sense, and is rooted Wittgenstein’s 'On Certainty'. On this account, normativity is intrinsic to human action and language; the norms of ethics are the logical limits of the most basic, unassailable concepts that practical reasoning requires for intelligibility. Part I lays the groundwork for this account by developing a Tractarian Reading of 'On Certainty'. Here, I contend that 'On Certainty' is primarily concerned (...) with the logical requirements and limits of language, and like the 'Tractatus' it develops these concerns in a realist direction. 'On Certainty', I argue, does so by advancing three key claims about logic: Everything descriptive of a language-game is part of logic; the boundary between logical and empirical propositions is not sharp; logic is founded on action. I investigate these claims, with particular emphasis on how natural human reactions provide logical conditions for the possibility of language. Hinge propositions, I argue, are rooted in these reactions; they point us to the limits of intelligibility of our concepts, though these limits are vague and inarticulable. In Part II, I discuss the practical syllogism and its validity. I argue that practical reasoning is distinct from theoretical reasoning and embodies a different standard of logical validity for inference. This standard is not strict and narrow, but creative and wide open; furthermore, it is an intrinsically ethical standard. Then, I advance my Linguistic Perspective on ethics, according to which human reactions provide the conditions for ethical normativity, just as they do for language. I argue that we can access ethical norms by reflecting on those linguistic concepts that are rooted in the most basic patterns of action, and by identifying the norms of behaviour that ensure the development of those concepts without contradiction. (shrink)