I mean a motion that proceeds from something numerically one and the same to something numerically one and the same in a period of time numerically one and the same; for a motion may be the same generically, specifically, or numerically: it is generically the same if it is of the same category, eg substance or quality; it is specifically the same if it proceeds from something specifically the same to something specifically the same, eg from white to black or from good to bad, which is not of a kind specifically distinct; it is numerically the same if it proceeds from something numerically one to something numerically one in the same time, eg from a particular white to a particular black, or from a particular place to a particular place, in a particular time; for if the time were not one and the same, the motion would no longer be numerically one though it would still be specifically one.