In this paper, I consider the role of exact symmetries in theories of physics, working throughout with the example of gravitation set in Newtonian spacetime. First, I spend some time setting up a means of thinking about symmetries in this context; second, I consider arguments from the seeming undetectability of absolute velocities to an anti-realism about velocities; and finally, I claim that the structure of the theory licences (and perhaps requires) us to interpret models which differ only with regards to the absolute velocities of objects as depicting the same physical state of affairs. In defending this last claim, I consider how ideas and resources from the philosophy of language may usefully be brought to bear on this topic.
Throughout his philosophical development, Wittgenstein was more concerned with language than with any other topic. No other philosopher has been as influential on our understanding of the deep problems surrounding language, and yet the true significance of his writing on the subject is difficult to assess, since most of the current debates regarding language tend to overlook his work. In this book, Thomas McNally shows that philosophers of language still have much to learn from Wittgenstein's later writings. The book examines the finer details of his arguments while also clarifying their importance for debates outside the field of Wittgenstein studies. Presenting the issues thematically (as they relate to questions of reference, scepticism about meaning, and the social dimension of language, among others), the book explores how the arguments in the Philosophical Investigations remain relevant, compelling us to reflect in novel and challenging ways on the nature of language.