(2) The part of human philosophy which is rational is of all knowledges, to the most wits, the least delightful, and seemeth but a net of subtlety and spinosity.  For as it was truly said, that knowledge is pabulum animi; so in the nature of men’s appetite to this food most men are of the taste and stomach of the Israelites in the desert, that would fain have returned ad ollas carnium, and were weary of manna; which, though it were celestial, yet seemed less nutritive and comfortable.  So generally men taste well knowledges that are drenched in flesh and blood, civil history, morality, policy, about the which men’s affections, praises, fortunes do turn and are conversant.  But this same lumen siccum doth parch and offend most men’s watery and soft natures.  But to speak truly of things as they are in worth, rational knowledges are the keys of all other arts, for as Aristotle saith aptly and elegantly, “That the hand is the instrument of instruments, and the mind is the form of forms;” so these be truly said to be the art of arts.  Neither do they only direct, but likewise confirm and strengthen; even as the habit of shooting doth not only enable to shoot a nearer shoot, but also to draw a stronger bow.

(3) The arts intellectual are four in number, divided according to the ends whereunto they are referred—­for man’s labour is to invent that which is sought or propounded; or to judge that which is invented; or to retain that which is judged; or to deliver over that which is retained.  So as the arts must be four—­art of inquiry or invention; art of examination or judgment; art of custody or memory; and art of elocution or tradition.

XIII. (1) Invention is of two kinds much differing—­the one of arts and sciences, and the other of speech and arguments.  The former of these I do report deficient; which seemeth to me to be such a deficience as if, in the making of an inventory touching the state of a defunct, it should be set down that there is no ready money.  For as money will fetch all other commodities, so this knowledge is that which should purchase all the rest.  And like as the West Indies had never been discovered if the use of the mariner’s needle had not been first discovered, though the one be vast regions, and the other a small motion; so it cannot be found strange if sciences be no further discovered, if the art itself of invention and discovery hath been passed over.

(2) That this part of knowledge is wanting, to my judgment standeth plainly confessed; for first, logic doth not pretend to invent sciences, or the axioms of sciences, but passeth it over with a cuique in sua arte credendum.  And Celsus acknowledgeth it gravely, speaking of the empirical and dogmatical sects of physicians, “That medicines and cures were first found out, and then after the reasons and causes were discoursed; and not the causes first found out, and by light from them the medicines and cures discovered.”  And Plato in his “Theaetetus”