Time and education beget experience; experience begets memory; memory begets judgment and fancy; judgment begets the strength and structure, and fancy begets the ornaments of a poem. The ancients therefore fabled not absurdly, in making Memory the mother of the Muses. For memory is the world, though not really, yet so as in a looking-glass, in which the judgment, the severer sister, busieth herself in a grave and rigid examination of all the parts of nature, and in registering by letters their order, causes, uses, differences, and resemblances; whereby the fancy, when any work of art is to be performed, finds her materials at hand and prepared for use, and needs no more than a swift motion over them, that what she wants, and is there to be had, may not lie too long unespied. So that when she seemeth to fly from one Indies to the other, and from heaven to earth, and to penetrate into the hardest matter and obscurest places, into the future, and into herself, and all this in a point of time, the voyage is not very great, herself being all she seeks. And her wonderful celerity, consisteth not so much in motion, as in copious imagery discreetly ordered, and perfectly registered in the memory; which most men under the name of philosophy have a glimpse of, and is pretended to by many, that grossly mistaking her, embrace contention in her place. But so far forth as the fancy of man has traced the ways of true philosophy, so far it hath produced very marvellous effects to the benefit of mankind. All that is beautiful or defensible in building; or marvellous in engines and instruments of motion; whatsoever commodity men receive from the observations of the heavens, from the description of the earth, from the account of time, from walking on the seas; and whatsoever distinguisheth the civility of Europe, from the barbarity of the American savages; is the workmanship of fancy, but guided by the precepts of true philosophy. But where these precepts fail, as they have hitherto failed in the doctrine of moral virtue, there the architect Fancy must take the philosopher’s part upon herself. He, therefore, who undertakes an heroic poem, which is to exhibit a venerable and amiable image of heroic virtue, must not only be the poet, to place and connect, but also the philosopher, to furnish and square his matter; that is, to make both body and soul, colour and shadow of his poem out of his own store; which, how well you have performed I am now considering.