As a fruit of the English residence, we must briefly notice the treatise, _de duplici copia verborum et rerum_,[97] written by Erasmus, as he says, at the request of Colet, and dedicated to him in a really beautiful and touching preface. The _Copia_ of Erasmus is a text-book of rhetoric, intended for advanced Latin scholars who have already mastered the principles of grammar and are well on the way to the acquisition of a good style. Its value for our purpose is in giving a clue to the principles of composition which were to govern Erasmus in all his writing; and thus preparing us to interpret what he says with the greater intelligence. No opinion as to his meaning on any question can be worth much which is not based upon a clear comprehension of his literary method. He was a literary artist and we are here introduced to some of the most valuable secrets of his art. They must never be forgotten when we try to find out what he really means at a given moment. [97] i., pp. 1-110. The word _copia_ is a difficult one to translate. Its first meaning of "abundance" is liable, as Erasmus begins by showing, to be understood as mere verbosity. "We see not a few mortals, who, striving to emulate this divine virtue with more zeal than success, fall into a feeble and disjointed loquacity, obscuring the subject and burdening the wretched ears of their hearers with a vacant mass of words and sentences crowded together beyond all possibility of enjoyment. And writers who have tried to lay down the principles of this art have gained no other result than to display their own poverty while expounding abundance." He proposes to give only certain directions, and to illustrate them by formulas which may prove convenient to writers. _Copia_ includes the ideas of richness and variety, but must avoid the errors of mere quantity and change. Not all fulness contributes to completeness of effect, and not all variation in style helps towards real illustration of the thought. Here, as elsewhere, we find Erasmus the true apostle of common-sense. After all, the purpose of rhetoric is primarily to say something worth saying, and to say it in such a way that it will commend itself to the reader. The purpose of these directions will therefore be to show how the essential point may be condensed into few words and yet nothing be left out, and how, on the other hand, one may expand into _copia_ and yet have nothing in superfluity. The first rule of the _Copia verborum_ is