In 'The Parleyings' the discussions turn principally upon artistic problems and their relation to modern philosophy, four out of the seven being inspired by artist, poet, or musician. The forgotten worthies whom Browning rescued from oblivion, make their appeal to him upon various grounds that connect them with the present. Bernard de Mandeville evidently caught Browning's fancy because in his satirical poem 'The Grumbling Hive' he forestalled, by a defence of the Duke of Marlborough's war policy, the doctrine of the relativity of good and evil. One might have imagined that this subject had been exhausted in 'Ferishtah's Fancies,' but it seems to have had a great fascination for Browning, probably because the idea was a new one and he felt the need of thinking his way through all its implications. Fresh interest is added in this case because the objector in the argument was a contemporary of Browning's--Carlyle, whose well-known pessimism over the existence of evil is graphically presented. Browning clenches his side of the argument with an original and daring variation upon the Prometheus myth led up to by one of the most magnificent passages in the whole range of his poetry, and probably the finest example anywhere in literature of a description of nature as interpreted by the laws of cosmic evolution. He describes the effect of the sun-light in developing the life upon the earth, tracing it as far as the mind of man. But the mind of man is not satisfied with the purely physical and phenomenal. "What avails sun's earth-felt thrill To me? Mind seeks to see, Touch, understand, by mind inside me, The outside mind--whose quickening I attain To recognize--I only." But Prometheus offered an artifice whereby man's mind is satisfied. He drew Sun's rays into a focus plain and true. The very sun in little: made fire burn and henceforth do man service. Denuded of its scientific and mystical symbolism Browning makes the Prometheus myth teach his favorite doctrine, namely that the image of love formed in the human heart by means of the burning glass supplied by sense and feeling is a symbol of infinite love.