ION: 'Bend gently,' he says, 'in the polished chariot to the left of them, and urge the horse on the right hand with whip and voice; and slacken the rein. And when you are at the goal, let the left horse draw near, yet so that the nave of the well-wrought wheel may not even seem to touch the extremity; and avoid catching the stone (Il.).'

SOCRATES: Enough. Now, Ion, will the charioteer or the physician be the better judge of the propriety of these lines?

ION: The charioteer, clearly.

SOCRATES: And will the reason be that this is his art, or will there be any other reason?

ION: No, that will be the reason.

SOCRATES: And every art is appointed by God to have knowledge of a certain work; for that which we know by the art of the pilot we do not know by the art of medicine?

ION: Certainly not.

SOCRATES: Nor do we know by the art of the carpenter that which we know by the art of medicine?

ION: Certainly not.

SOCRATES: And this is true of all the arts;—that which we know with one art we do not know with the other? But let me ask a prior question: You admit that there are differences of arts?