To his pupil, worried over this problem, Ferishtah points out that evil in the form of bodily suffering has given rise to the beautiful sentiments of pity and sympathy. Having proved in this way that good really grows out of evil, there is still the query, shall evil be encouraged in order that good may be evolved? "No!" Ferishtah declares, man bound by man's conditions is obliged to estimate as "fair or foul right, wrong, good, evil, what man's faculty adjudges as such," therefore the man will do all he can to relieve the suffering or poor Mihrab Shah with a fig plaster. The final answers, then, which Browning gives to the ethical problems which grew out of the acceptance of modern scientific doctrines are, in brief, that man shall use that will-power of which he feels himself possessed--the power really distinguishing him from the brute creation--in working against whatever appears to him to be evil; while that good for which he shall work is the greatest happiness of all. In the remaining poems of the group we have the poet's mature word upon the philosophical doctrine of the relativity of knowledge, a doctrine which received the most elaborate demonstration from Herbert Spencer in many directions. It is insisted upon in "Cherries," "The Sun," in "A Bean Stripe also Apple Eating," and especially in that remarkable poem, "A Pillar at Sebzevar." That knowledge fails is the burden of these poems. Knowledge the golden is but lacquered ignorance, as gain to be mistrusted. Curiously enough, this contention of Browning's has been the cause of most of the criticisms against him as a thinker, yet the deepest thinkers of to-day as well as many in the past have held the opinion in some form or another that the intellect was unable to solve the mysterious problems of the universe. Even the metaphysicians who build their unstable air castles on _à priori_ ideas declare these ideas cannot be matters of mere intellectual perception, but must be intuitions of the higher reason. Browning, however, does not rest in the mere assertion that the intellect fails. From this truth, so disconcerting to many, he draws immense comfort. Though intellectual knowledge be mistrusted as gain, it is not to be mistrusted as means to gain, for through its very failure it becomes a promise of greater things. "Friend," quoth Ferishtah in "A Pillar of Sebzevar," "As gain--mistrust it! Nor as means to gain: Lacquer we learn by: cast in firing-pot, We learn--when what seemed ore assayed proves dross Surelier true gold's worth, guess how purity I' the lode were precious could one light on ore Clarified up to test of crucible. The prize is in the process: knowledge means Ever-renewed assurance by defeat That victory is somehow still to reach."