But we saw that actions are not merely relative to us, but possess a separate nature of their own?

True.

Then in naming also, if we are to be consistent with our previous conclusions, we cannot follow our own will, but the way and the instrument which the nature of things prescribes must be employed, must they not? And if we pursue this course we shall be successful in our naming, but otherwise we shall fail.

I think you are right.

And again, what has to be cut, we said, has to be cut with something.

Certainly.