YOUNG SOCRATES: True.
STRANGER: Then the next thing will be to separate them, in order that the argument may proceed in a regular manner?
YOUNG SOCRATES: By all means.
STRANGER: Let us consider, in the first place, that there are two kinds of arts entering into everything which we do.
YOUNG SOCRATES: What are they?
STRANGER: The one kind is the conditional or co-operative, the other the principal cause.
YOUNG SOCRATES: What do you mean?
STRANGER: The arts which do not manufacture the actual thing, but which furnish the necessary tools for the manufacture, without which the several arts could not fulfil their appointed work, are co-operative; but those which make the things themselves are causal.
YOUNG SOCRATES: A very reasonable distinction.
STRANGER: Thus the arts which make spindles, combs, and other instruments of the production of clothes, may be called co-operative, and those which treat and fabricate the things themselves, causal.