From the conception of mechanical force as coming in  from Nature to the service of man, a conception the Utopian proposal of a  coinage based on energy units would emphasise, arise profound contrasts  between the modern and the classical Utopias. Except for a meagre use  of water power for milling, and the wind for sailing — so meagre in the  latter case that the classical world never contrived to do without the  galley slave — and a certain restricted help from oxen in ploughing, and  from horses in locomotion, all the energy that sustained the  old-fashioned State was derived from the muscular exertion of toiling  men. They ran their world by hand. Continual bodily labour was a  condition of social existence. It is only with the coming of coal  burning, of abundant iron and steel, and of scientific knowledge that  this condition has been changed. To-day, I suppose, if it were possible  to indicate, in units of energy, the grand total of work upon which the  social fabric of the United States or England rests, it would be found  that a vastly preponderating moiety is derived from non-human sources,  from coal and liquid fuel, and explosives and wind and water. There is  every indication of a steady increase in this proportion of mechanical  energy, in this emancipation of men from the necessity of physical  labour. There appears no limit to the invasion of life by the machine.
Now  it is only in the last three hundred years that any human being seems  to have anticipated this. It stimulates the imagination to remark how  entirely it was overlooked as a modifying cause in human development.  [Footnote: It is interesting to note how little even Bacon seems to see  of this, in his New Atlantis.] Plato clearly had no ideas about machines  at all as a force affecting social organisation. There was nothing in  his world to suggest them to him. I suppose there arose no invention, no  new mechanical appliance or method of the slightest social importance  through all his length of years. He never thought of a State that did  not rely for its force upon human muscle, just as he never thought of a  State that was not primarily organised for warfare hand to hand.  Political and moral inventions he saw enough of and to spare, and in  that direction he still stimulates the imagination. But in regard to all  material possibilities he deadens rather than stimulates. [Footnote:  The lost Utopia of Hippodamus provided rewards for inventors, but unless  Aristotle misunderstood him, and it is certainly the fate of all  Utopias to be more or less misread, the inventions contemplated were  political devices.] An infinitude of nonsense about the Greek mind would  never have been written if the distinctive intellectual and artistic  quality of Plato’s time, its extraordinarily clear definition of certain  material conditions as absolutely permanent, coupled with its  politico-social instability, had been borne in mind. The food of the  Greek imagination was the very antithesis of our own nourishment. We are  educated by our circumstances to think no revolution in appliances and  economic organisation incredible, our minds play freely about  possibilities that would have struck the men of the Academy as  outrageous extravagance, and it is in regard to politico-social  expedients that our imaginations fail. Sparta, for all the evidence of  history, is scarcely more credible to us than a motor-car throbbing in  the agora would have been to Socrates.
By sheer inadvertence,  therefore, Plato commenced the tradition of Utopias without machinery, a  tradition we find Morris still loyally following, except for certain  mechanical barges and such-like toys, in his News from Nowhere. There  are some foreshadowings of mechanical possibilities in the New Atlantis,  but it is only in the nineteenth century that Utopias appeared in which  the fact is clearly recognised that the social fabric rests no longer............
				  
				   