But if any man undertake to write a history, that has to be collected from materials gathered by observation and the reading of works not easy to be got in all places, nor written always in his own language, but many of them foreign and dispersed in other hands, for him, undoubtedly, it is in the first place and above all things most necessary, to reside in some city of good note, addicted to liberal arts, and populous; where he may have plenty of all sorts of books, and upon inquiry may hear and inform himself of such particulars as, having escaped the pens of writers, are more faithfully preserved in the memories of men, lest his work be deficient in many things, even those which it can least dispense with.