" Then without determining as yet whether war does good or harm, thus much we may affirm, that now we have discovered war to be derived from causes which are also the causes of almost all the evils in States, private as well as public. Undoubtedly. And our State must once more enlarge; and this time the enlargement will be nothing short of a whole army, which will have to go out and fight with the invaders for all that we have, as well as for the things and persons whom we were describing above. Why? he said; are they not capable of defending themselves? No, I said; not if we were right in the principle which was acknowledged by all of us when we were framing the State: the principle, as you will remember, was that one man cannot practise many arts with success. Very "

― Plato , The Republic