Abstract

When an event occurs which involves a change from a state ϕ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\phi $$\end{document} to a state not-ϕ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\phi $$\end{document}, when does the change occur? This is known in the philosophical literature as the problem of the moment of change. I discuss a puzzle based on this problem raised by Sextus Empiricus in Against the Physicists. I compare two lines of solution, one provided by Hans Kamp’s work on the logic of change and the other inspired by Aristotle’s claim that change cannot happen at an instant. I end with a discussion of these solutions vis-à-vis the account of cessation implicatures proposed by Altshuler and Schwarzschild.