THE SECOND BOOK. 93 



that as tennis is a game of no use in itself, but of great use in 

 respect it maketh a quick eye and a body ready to put itself 

 into all postures, so in the mathematics that use which is 

 collateral and intervenient is no less worthy than that which is 

 principal and intended. And as for the mixed mathematics, I 

 may only make this prediction, that there cannot fail to be 

 more kinds of them as Nature grows further disclosed. Thus 

 much of natural science, or the part of Nature speculative. 



(3) For natural prudence, or the part operative of natural 

 philosophy, we will divide it into three parts experimental, 

 philosophical, and magical ; which three parts active have a 

 correspondence and analogy with the three parts speculative, 

 natural history, physic, and metaphysic. For many operations 

 have been invented, sometimes by a casual incidence and 

 occurrence, sometimes by a purposed experiment ; and of those 

 which have been found by an intentional experiment, some 

 have been found out by varying or extending the same experi 

 ment, some by transferring and compounding divers experi 

 ments the one into the other, which kind of invention an 

 empiric may manage. Again, by the knowledge of physical 

 causes there cannot fail to follow many indications and designa 

 tions of new particulars, if men in their speculation will keep 

 one eye upon use and practice. But these are but coastings 

 along the shore, premendo littus iniquum ; for it seemeth to 

 me there can hardly be discovered any radical or fundamental 

 alterations and innovations in Nature, either by the fortune and 

 essays of experiments, or by the light and direction of physical 

 causes. If, therefore, we have reported metaphysic deficient, 

 it must follow that we do the like of natural magic, which hath 

 relation thereunto. For as for the natural magic whereof 

 now there is mention in books, containing certain credulous 

 and superstitious conceits and observations of sympathies and 

 antipathies, and hidden proprieties, and some frivolous experi 

 ments, strange rather by disguisement than in themselves, it 

 is as far differing in truth of Nature from such a knowledge 

 as we require as the story of King Arthur of Britain, or Hugh 

 of Bourdeaux, differs from Caesar s Commentaries in truth of 

 story ; for it is manifest that Caesar did greater things de v&ro 

 than those imaginary heroes were feigned to do. But he did 

 them not in that fabulous manner. Of this kind of learning 

 the fable of Ixion was a figure, who designed to enjoy Juno, the 

 goddess of power, and instead of her had copulation with a 

 cloud, of which mixture were begotten centaurs and chimeras. 

 So whosoever shall entertain high and vaporous imaginations, 

 instead of a laborious and sober inquiry of truth, shall beget 



