cannot be beginningless.”
They may be asked:
“By saying that motion entails being preceded by something else, do you mean that some of its parts precede others—which is the meaning you have argued for? Or do you mean that it is preceded by nonexistence, or by its agent?
“As for the first—which is what you have argued for—it entails the opposite of your position: that motion has always existed as a kind. For every motion is preceded by another motion, and every state into which a moving thing passes is preceded by another state, which in turn is preceded by another. Thus, what you have cited as proof that motion has a temporal beginning, while establishing that particular motions and their parts have a temporal beginning, also establishes the perpetuity of the kind—the opposite of your position.
“Thus, what you have advanced as evidence on the disputed point establishes only matters on which there is agreement. On the disputed point, it is evidence against you, not for you.”
The disputant may then say:
“We accept what your proof entails, and it is evidence against you.
“If you mean that what is designated by ‘motion’ is preceded by nonexistence, you have offered no proof whatsoever for this, and this is precisely the point at issue.
“If you mean that it is preceded by its agent, this, too, can mean that each of its parts is preceded by its agent. It can also mean that the agent preceded the kind, existing separately from it. And if they have not established this by proof, then you have offered no proof for the position you have adopted; what you have proved supports not your position but its opposite.”
For this reason, their opponents, the philosophers, may be told:
“You have offered no proof that anything in the world is beginningless. Rather, most of the proofs you have offered entail the perpetuity of agency. This indicates the opposite of your position, for it entails that the agent has always been acting, whereas anything brought into being can only be something that comes into existence after not existing.”