it; if too wandering, they fix it; if too inherent in the sense, they abstract it. So 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.

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 experiment, some by transferring and compounding divers experiments, 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 designations 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, Naturalis it must follow, that we do the like of natural magic, magia sive physica which hath relation thereunto. For as for the natural operativa magic whereof now there is mention in books, contain- major. ing certain credulous and superstitious conceits and observations of sympathies, and antipathies, and hidden

proprieties, and some frivolous experiments, 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 Cæsar's commentaries in truth of story. For it is manifest that Cæsar did greater things de vero, 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 hopes and beliefs of strange and impossible shapes. And therefore we may note in these sciences, which hold so much of imagination and belief, as this degenerate natural magic, alchemy, astrology, and the like, that, in their propositions, the description of the means is ever more monstrous than the pretence or end.

For it is a thing more probable, that he that knoweth well the natures of weight, of colour, of pliant and fragile in respect of the hammer, of volatile and fixed in respect of the fire, and the rest, may superinduce upon some metal the nature and form of gold by such mechanic as longeth to the production of the natures afore rehearsed, than that some grains of the medicine projected should in a few moments of time turn a sea of quicksilver, or other material, into gold: so it is more probable, that he, that knoweth the nature of arefaction, the nature of assimilation, of nourishment to the thing nourished, the manner of increase and clearing of spirits, the manner of the depredations which spirits make upon the humours and solid parts; shall, by ambages of diets, bathings, anointings, medicines, motions, and the like, prolong life, or restore some degree of youth or vivacity, than that it can be done with the use of a few drops, or scruples of a liquor or receipt. To con

humana

clude therefore, the true natural magic, which is that great liberty and latitude of operation which dependeth upon the knowledge of forms, I may report deficient, as the relative thereof is; to which part, if we be serious, and incline not to vanities and plausible discourse, besides the deriving and deducing the operations themselves from metaphysic, there are pertinent two points of much purpose, the one by way of preparation, the other by way of caution: the first is, that there be made a kalendar resembling an inven- Inventaritory of the estate of man, containing all the inven- um opum tions, being the works or fruits of nature or art, which rum. are now extant, and whereof man is already possessed, out of which doth naturally result a note, what things are yet held impossible or not invented: which kalendar will be the more artificial and serviceable, if to every reputed impossibility you add what thing is extant, which cometh the nearest in degree to that impossibility; to the end, that by these optatives and potentials man's inquiry may be the more awake in deducing direction of works from the speculation of causes and secondly, that those experiments be not only esteemed which have an immediate and present use, but those principally which are of most universal consequence for invention of other experiments, and those which give most light to the invention of causes: for the invention of the mariner's needle, which giveth the direction, is of no less benefit for navigation, than the invention of the sails, which give the motion.

Thus have I passed through natural philosophy, and the deficiencies thereof, wherein if I have differed from the ancient and received doctrines, and thereby shall move contradiction; for my part, as I affect not to dissent, so I purpose not to contend. If it be truth, Non canimus surdis, respondent omnia sylvæ: the voice of nature will consent, whether the voice of man do or no. And as Alexander Borgia was wont to say of the expedition of the French for Naples, that they came with chalk in their hands to mark up their lodgings, and not with weapons to fight: so I like better that entry of truth, which cometh peaceably

with chalk to mark up those minds which are capable to lodge and harbour it, than that which cometh with pugnacity and contention.

But there remaineth a division of natural philosophy according to the report of the inquiry, and nothing concerning the matter or subject; and that is positive and considerative; when the inquiry reporteth either an assertion, or a doubt. These doubts, or non liquets, are of two sorts, particular, and total. For the first, we see a good example thereof in Aristotle's Problems, which deserved to have had a better continuance; but so nevertheless, as there is one point whereof warning is to be given and taken. The registring of doubts hath two excellent uses: The one, that it saveth philosophy from errors and falsehoods, when that which is not fully appearing is not collected into assertion, whereby error might draw error, but reserved in doubt. The other, that the entry of doubts are as so many suckers or spunges to draw use of knowledge; insomuch, as that which, if doubts had not preceded, a man should never have advised, but passed it over without note, by the suggestion and solicitation of doubts is made to be attended and applied. But both these commodities do scarcely countervail an inconvenience which will intrude itself, if it be not debarred; which is, that, when a doubt is once received, men labour rather how to keep it a doubt still, than how to solve it, and accordingly bend their wits. Of this we see the familiar example in lawyers and scholars, both which, if they have once admitted a doubt, it goeth ever after authorized for a doubt. But that use of wit and knowledge is to be allowed, which laboureth to make doubtful things certain, and not those which Continuatio labour to make certain things doubtful. Therefore problema- these kalendars of doubts I commend as excellent things, so that there be this caution used, that when they be throughly sifted and brought to resolution, they be from thenceforth omitted, discarded, and not continued to cherish and encourage men in doubting. To which kalendar of doubts or problems, I advise to be annexed another kalendar, as much or more mate

tum in natu

ra.

grassan

rial, which is a kalendar of popular errors, I mean Catalogus chiefly in natural history, such as pass in speech and falsitatum conceit, and are nevertheless apparently detected and um in convicted of untruth, that man's knowledge be not historia weakened nor embased by such dross and vanity.

naturæ.

As for the doubts or non liquets general or in total, I understand those differences of opinions touching the principles of nature, and the fundamental points of the same, which have caused the diversity of sects, schools, and philosophies, as that of Empedocles, Pythagoras, Democritus, Parmenides, and the rest. For although Aristotle, as though he had been of the race of the Ottomans, thought he could not reign, except the first thing he did he killed all his brethren; yet to those that seek truth and not magistrality, it cannot but seem a matter of great profit, to see before them the several opinions touching the foundations of nature: not for any exact truth that can be expected in those theories for as the same phænomena in astronomy are satisfied by the received astronomy of the diurnal motion, and the proper motions of the planets, with their eccentrics, and epicycles; and likewise by the theory of Copernicus, who supposed the earth to move, and the calculations are indifferently agreeable to both: so the ordinary face and view of experience is many times satisfied by several theories and philosophies; whereas to find the real truth requireth another manner of severity and attention. For, as Aristotle saith, that children at the first will call every woman mother, but afterward they come to distinguish according to truth so experience, if it be in childhood, will call every philosophy mother, but when it cometh to ripeness, it will discern the true mother; so as in the mean time it is good to see the several glosses and opinions upon nature, whereof it may be every one in some one point hath seen clearer than his fellows; therefore I wish some collection to be made painfully and understandingly de antiquis philosophiis, out of De antiall the posible light which remaineth to us of them: quis philowhich kind of work I find deficient. But here I must give warning, that it be done distinctly and severally,

sophiis.