  The argument that Socrates presents on the Heracleiteans’ behalf infers from “Everything is always changing in every way” that “No description of anything is excluded.” How does this follow?  McDowell 1976: 181–2 finds the missing link in the impossibility of identifications. We cannot (says McDowell) identify a moving sample of whiteness, or of seeing, any longer once it has changed into some other colour, or perception.