‘Honour Equality who binds together Both friends and cities and confederates, For equity is law, law equity; The lesser is the greater’s enemy, And disadvantaged aye begins the strife. From her our measures, weights, and numbers come, Defined and ordered by Equality; So do the night’s blind eye and sun’s bright orb Walk equal courses in their yearly round, And neither is embittered by defeat; And while both light and darkness serve mankind Wilt thou not bear an equal in thy house?’[62] On examining the apologue of Prodicus, we find it characterised by a somewhat similar style of reasoning. There is, it is true, no reference to physical phenomena, but Virtue dwells strongly on the truth that nothing can be had for nothing, and that pleasure must either be purchased by toil or atoned for by languor, satiety, and premature decay. We know also that the Cynical school, as represented by Antisthenês, rejected all pleasure on the ground that it was always paid for by an equal amount of pain; and Heraclês, the Prodicean type of a youth who follows virtue in preference to vice disguised as happiness, was also the favourite hero of the Cynics. Again, Plato alludes, in the _Philêbus_, to certain thinkers, reputed to be ‘great on the subject of physics,’ who deny the very existence of pleasure. Critics have been at a loss to identify these persons, and rather reluctantly put up with the explanation that Antisthenês and his school are referred to. Antisthenês was a friend of Prodicus, and may at one time have shared in his scientific studies, thus giving occasion to the association touched on by Plato. But is it not equally possible that Prodicus left behind disciples who, like him, combined moral with physical teaching; and, going a little further, may we not conjecture that their opposition to Hedonism was inherited from the master himself, who, like the Stoics afterwards, may have based it on an application of physical reasoning to ethics?