On Architecture

14. Still, it is not architects alone that cannot in all matters each perfection, but even men who individually practise specialties in the arts do not all attain to the highest point of merit. Therefore, if among artists working each in a single field not all, only a few in an entire generation acquire fame, and that with difficulty, how can an architect, who has to be skilful in many accomplish not merely the feat—in itself a great marvel—of being deficient in none of them, but also that of surpassing all those artists who have devoted themselves with unremitting industry to single fields?

15. It appears, then, that Pytheos made a mistake by not observing that the arts are each composed of two things, the actual and the theory of it. One of these, the doing of the work, is