It was strange enough that any poem should arise by such means; but it would have been miraculous if a poem so constructed had been at once a demonstration and an exposition of a harmonious philosophical system. The confession which he made to Warburton will be a sufficient indication of his qualifications as a student. He says (in 1739) that he never in his life read a line of Leibnitz, nor knew, till he found it in a confutation of his Essay, that there was such a term as pre-established harmony. That is almost as if a modern reconciler of faith and science were to say that he had never read a line of Mr. Darwin, or heard of such a phrase as the struggle for existence. It was to pronounce himself absolutely disqualified to speak as a philosopher. How, then, could Pope obtain even an appearance of success? The problem should puzzle no one at the present day. Every smart essayist knows how to settle the most abstruse metaphysical puzzles after studies limited to the pages of a monthly magazine; and Pope was much in the state of mind of such extemporizing philosophers. He had dipped into the books which everybody read; Locke's Essay, and Shaftesbury's Characteristics, and Wollaston's Religion of Nature, and Clarke on the Attributes, and Archbishop King on the Origin of Evil, had probably amused his spare moments. They were all, we may suppose, in Bolingbroke's library; and if that passing shower commemorated in Pope's letter drove them back to the house, Bolingbroke might discourse from the page which happened to be open, and Pope would try to versify it on the back of an envelope.[20] Nor must we forget, like some of his commentators, that after all Pope was an exceedingly clever man. His rapidly perceptive mind was fully qualified to imbibe the crude versions of philosophic theories which float upon the surface of ordinary talk, and are not always so inferior to their prototypes in philosophic qualities, as philosophers would have us believe. He could by snatches seize with admirable quickness the general spirit of a doctrine, though unable to sustain himself at a high intellectual level for any length of time. He was ready with abundance of poetical illustrations, not, perhaps, very closely adapted to the logic, but capable of being elaborated into effective passages; and, finally, Pope had always a certain number of more or less appropriate commonplaces or renderings into verse of some passages which had struck him in Pascal, or Rochefoucauld, or Bacon, all of them favourite authors, and which could be wrought into the structure at a slight cost of coherence. By such means he could put together a poem, which was certainly not an organic whole, but which might contain many striking sayings and passages of great rhetorical effect.