From this conception of poetry as a storehouse of practical wisdom the transition is easy to a purely ethical judgment of its value; and that transition, as has been already noted, was actually made by Plato, who even goes so far as to prescribe to poets the direct inculcation of such morals as are proper to a tract, as that the good and just man is happy even though he be poor, and the bad and unjust man miserable even though he be rich. This didacticism, no doubt, is a parody; but it is a parody of the normal Greek view, that the excellence of a poem is closely bound up with the compass and depth of its whole ethical content, and is not to be measured, as many moderns maintain, merely by the aesthetic beauty of its form. When Strabo says, "it is impossible to be a good poet unless you are first a good man," he is expressing the common opinion of the Greeks that the poet is to be judged not merely as an artist but as an interpreter of life; and the same presupposition underlies the remark of Aristotle that poets may be classified according as the characters they represent are as good as, better, or worse than the average man. But perhaps the most remarkable illustration of this way of regarding poetry is the passage in the "Frogs" of Aristophanes, where the comedian has introduced a controversy between Aeschylus and Euripides as to the relative merit of their works, and has made the decision turn almost entirely on moral considerations, the question being really whether or no Euripides is to be regarded as a corrupter of his countrymen. In the course of the discussion Aeschylus is made to give expression to a view of poetry which clearly enough Aristophanes endorses himself, and which no doubt would be accepted by the majority of his audience. He appeals to all antiquity to shew that poets have always been the instructors of mankind, and that it is for this that they are held in honour. "Look to traditional history, look To antiquity, primitive, early, remote; See there, what a blessing illustrious poets Conferr'd on mankind, in the centuries past. Orpheus instructed mankind in religion, Reclaim'd them from bloodshed and barbarous rites; Musaeus deliver'd the doctrine of med'cine, And warnings prophetic for ages to come; Next came old Hesiod, teaching us husbandry, Ploughing, and sowing, and rural affairs, Rural economy, rural astronomy, Homely morality, labour, and thrift; Homer himself, our adorable Homer, What was his title to praise and renown? What, but the worth of the lessons he taught us Discipline, arms, and equipment of war?" [Footnote: Aristoph. Frogs, 1030.--Translated by Frere.]