STRANGER: Then, not to exclude any one who has ever speculated at all upon the nature of being, let us put our questions to them as well as to our former friends.
THEAETETUS: What questions?
STRANGER: Shall we refuse to attribute being to motion and rest, or anything to anything, and assume that they do not mingle, and are incapable of participating in one another? Or shall we gather all into one class of things communicable with one another? Or are some things communicable and others not?—Which of these alternatives, Theaetetus, will they prefer?
THEAETETUS: I have nothing to answer on their behalf. Suppose that you take all these hypotheses in turn, and see what are the consequences which follow from each of them.
STRANGER: Very good, and first let us assume them to say that nothing is capable of participating in anything else in any respect; in that case rest and motion cannot participate in being at all.
THEAETETUS: They cannot.
STRANGER: But would either of them be if not participating in being?
THEAETETUS: No.
STRANGER: Then by this admission everything is instantly overturned, as well the doctrine of universal motion as of universal rest, and also the doctrine of those who distribute being into immutable and everlasting kinds; for all these add on a notion of being, some affirming that things 'are' truly in motion, and others that they 'are' truly at rest.
THEAETETUS: Just so.