But to dwell on the multitude of portraits with which Browning's keen observation, memory and love of human nature have embellished _The Ring and the Book_ belongs to another part of this chapter. At present the question rises: "What place does _The Ring and the Book_ hold in Browning's development?" It holds a central place. There was always a struggle in Browning between two pleasures; pleasure in the exercise of his intellect--his wit, in the fullest sense of the word; pleasure in the exercise of his poetic imagination. Sometimes one of these had the upper hand in his poems, sometimes the other, and sometimes both happily worked together. When the exercise of his wit had the upper hand, it tended to drive out both imagination and passion. Intellectual play may be without any emotion except its delight in itself. Then its mere cleverness attracts its user, and gives him an easily purchased pleasure. When a poet falls a complete victim to this pleasure, imagination hides her face from him, passion runs away, and what he produces resembles, but is not, poetry. And Browning, who had got perilously near to the absence of poetry in _Bishop Blougram's Apology_, succeeded in _Mr. Sludge, the Medium_, in losing poetry altogether. In _The Ring and the Book_ there are whole books, and long passages in its other books in which poetry almost ceases to exist and is replaced by brilliant cleverness, keen analysis, vivid description, and a combination of wit and fancy which is rarely rivalled; but no emotion, no imagination such as poets use inflames the coldness of these qualities into the glow of poetry. The indefinable difference which makes imaginative work into poetry is not there. There is abundance of invention; but that, though a part of imagination, belongs as much to the art of prose as to the art of poetry.