Wittgenstein on formulae

This paper discusses Wittgenstein's treatment of formulae. In particular, it will be shown that although Wittgenstein frequently investigates both equations (e.g. x ² + 1 = 0, ^ _xx(x - 1) = x ² - x) and formulae in a narrow sense (e.g. sin 2x, r ²π), he rarely addresses the two together, let alone discusses the latter as parts of equations. Two issues will be raised for which this is of especial consequence. This sheds light on the change that Wittgenstein's understanding of the relation between formulae and generality underwent between the so-called middle phase and the Remarks on the Foundations of Mathematics.