Its now three years since I ended the Treatise which contains all these things, and that I began to review it, to send it afterwards to the Presse, when I understood, that persons to whom I submit, and whose authority can no lesse command my actions, then my own Reason doth my thoughts, had disapproved an opinion in Physicks, published a little before by another; of which I will not say that I was, but that indeed I had observed nothing therein, before their censure, which I could have imagined prejudiciall either to Religion or the State; or consequently, which might have hindred me from writing the same, had my Reason perswaded mee thereto. And this made me fear, lest in the same manner there might be found some one amongst mine, in which I might have been mistaken; notwithstanding the great care I always had to admit no new ones into my belief, of which I had not most certain demonstrations; and not to write such as might turn to the disadvantage of any body. Which was sufficient to oblige me to change my resolution of publishing them. For although the reasons for which I had first of all taken it, were very strong; yet my inclination, which alwayes made me hate the trade of Book-making, presently found me out others enough to excuse my self from it. And these reasons on the one and other side are such, that I am not only somewhat concern'd to speak them; but happily the Publick also to know them.
I never did much esteem those things which proceeded from mine own brain; and so long as I have gathered no other fruits from the Method I use, but onely that I have satisfied my self in some difficulties which belong to speculative Sciences, or at least endeavoured to regulate my Manners by the reasons it taught me, I thought my self not obliged to write any thing of them. For, as for what concerns Manners, every one abounds so much in his own sense, That we may finde as many Reformers as heads, were it permitted to others, besides those whom God hath established as Soveraigns over his people, or at least, to whom he hath dispensed grace and zeal enough to be Prophets, to undertake the change of any thing therein. And although my Speculations did very much please me, I did beleeve that other men also had some, which perhaps pleas'd them more. But as soon as I had acquired some generall notions touching naturall Philosophy, and beginning to prove them in divers particular difficulties, I observed how far they might lead a man, and how far different they were from the principles which to this day are in use; I judg'd, that I could not keep them hid without highly sinning against the Law, which obligeth us to procure, as much as in us lies, the general good of all men. For they made it appear to me, that it was possible to attain to points of knowledge, which may be very profitable for this life: and that in stead of this speculative Philosophy which is taught in the Schools, we might finde out a practicall one, by which knowing the force and workings of Fire, Water, Air, of the Starrs, of the Heavens, and of all other Bodies which environ us, distinctly, as we know the several trades of our Handicrafts, we might in the same manner employ them to all uses to which they are fit, and so become masters and possessours of Nature. Which is not onely to be desired for the invention of very many expedients of Arts, which without trouble might make us enjoy the fruits of the earth, and all the conveniences which are to be found therein: But chiefly also for the preservation of health, which (without doubt) is the first good, and the foundation of all other good things in this life. For even the minde depends so much on the temper and disposition of the organs of the body, that if it be possible to finde any way of making men in the generall wiser, and more able then formerly they were, I beleeve it ought to be sought in Physick. True it is, that which is now in use contains but few things, whose benefit is very remarkable: But (without any designe of slighting of it) I assure my self, there is none, even of their own profession, but will consent, that whatsoever is known therein, is almost nothing in companion of what remains to be known. And that we might be freed from very many diseases, aswell of the body as of the mind, and even also perhaps from the weaknesses of old age, had we but knowledge enough of their Causes, and of all the Remedies wherewith Nature hath furnished us. Now having a designe to employ all my life in the enquiry of so necessary a Science; and having found a way, the following of which me thinks might infallibly lead us to it, unless we be hindred by the shortness of lifes, or by defect of experiments. I judg'd that there was no better Remedie against those two impediments, but faithfully to communicate to the publique, all that little I should discover, and to invite all good Wits to endevour to advance farther in contributing every one, according to his inclination and power, to those Experiments which are to be made, and communicating also to the publique all the things they should learn; so that the last, beginning where the precedent ended, and so joyning the lives and labors of many in one, we might all together advance further then any particular Man could do.
I also observ'd touching Experiments, that they are still so much the more necessary, as we are more advanc'd in knowledg. For in the beginning it's better to use those only which of themselves are presented to our senses, and which we cannot be ignorant of, if we do but make the least reflections upon them, then to seek out the rarest and most studied ones. The reason whereof is, that those which are rarest, doe often deceive, when we seldome know the same of the most common ones, and that the circumstances on which they depend, are, as it were, always so particular, and so small, that it's very uneasie to finde them out. But the order I observed herein was this. First, I endevoured to finde in generall the Principles or first Causes of whatsoever is or may be in the world, without considering any thing for this end, but God alone who created it, or drawing them elsewhere, then from certain seeds of Truth which naturally are in our souls. After this, I examined what were the first and most ordinary Effects which might be deduced from these Causes: And me thinks that thereby I found out Heavens, Starrs, an Earth; and even on the Earth, Water, Air and Fire, Minerals, and some other such like things, which are the most common, and the most simple of all, and consequently the most easie to be understood. Afterwards, when I would descend to those which were more particular, there were so many severall ones presented themselves to me, that I did beleeve it impossible for a humane understanding to distinguish the forms and species of Bodies which are on the earth, from an infinite number of others which might be there, had it been the will of God so to place them: Nor by consequence to apply them to our use, unless we set the Effects before the Causes, and make use of divers particular experiments; In relation to which, revolving in my minde all those objects which ever were presented to my senses, I dare boldly say, I observed nothing which I could not fitly enough explain by the principles I had found. But I must also confesse that the power of Nature is so ample and vast, and these principles are so simple and generall, that I can observe almost no particular Effect, but that I presently know it might be deduced from thence in many severall ways: and that commonly my greatest difficulty is to finde in which of these ways it depends thereon; for I know no other expedient for that, but again to seek some experiments, which may be such, that their event may not be the same, if it be in one of those ways which is to be exprest, as if it were in another. In fine, I am gotten so far, That (me thinks) I see well enough what course we ought to hold to make the most part of those experiments which may tend to this effect. But I also see they are such, and of so great a number, that neither my hands nor my estate (though I had a thousand times more then I have) could ever suffice for all. So that according as I shall hereafter have conveniency to make more or fewer of them, I shall also advance more or lesse in the knowledge of Nature, which I hop'd I should make known by the Treatise which I had written; and therein so clearly shew the benefit which the Publick may receive thereby, that I should oblige all those in general who desire the good of Mankinde; that is to say, all those who are indeed vertuous, (and not so seemingly, or by opinion only) aswell to communicate such experiments as they have already made, as to help me in the enquiry of those which are to be made.
But since that time, other reasons have made me alter my opinion, and think that I truly ought to continue to write of all those things which I judg'd of any importance, according as I should discover the truth of them, and take the same care, as if I were to print them; as well that I might have so much the more occasion throughly to examine them; as without doubt, we always look more narrowly to what we offer to the publick view, then to what we compose onely for our own use: and oftentimes the same things which seemed true to me when I first conceived them, appear'd afterwards false to me, when I was committing them to paper: as also that I might lose no occasion of benefiting the Publick, if I were able, and that if my Writings were of any value, those to whose hands they should come after my death, might to make what use of them they think fit.
But that I ought not any wayes to consent that they should be published during my life; That neither the opposition and controversies, whereto perhaps they might be obnoxious, nor even the reputation whatsoever it were, which they might acquire me, might give me any occasion of mispending the time I had design'd to employ for my instruction; for although it be true that every Man is oblig'd to procure, as much as in him lies, the good of others; and that to be profitable to no body, is properly to be good for nothing: Yet it's as true, that our care ought to reach beyond the present time; and that it were good to omit those things which might perhaps conduce to the benefit of those who are alive, when our designe is, to doe others which shall prove farr more advantagious to our posterity; As indeed I desire it may be known that the little I have learnt hitherto, is almost nothing in comparison of what I am ignorant of; and I doe not despair to be able to learn: For it's even the same with those, who by little and little discover the truth in Learning; as with those who beginning to grow rich, are less troubled to make great purchases, then they were before when they were poorer, to make little ones. Or else one may compare them to Generals of Armies, whose Forces usually encrease porportionably to their Victories; and who have need of more conduct to maintain themselves after the loss of a battail, then after the gaining one, to take Towns and Provinces. For to endeavour to overcome all the difficulties and errours which hinder us to come to the knowledg of the Truth, is truly to fight battails. And to receive any false opinion touching a generall or weighty matter, is as much as to lose one; there is far more dexterity required to recover our former condition, then to make great progresses where our Principles are already certain. For my part, if I formerly have discovered some Truths in Learning, as I hope my Discourse will make it appear I have, I may say, they are but the products and dependances of five or six principall difficulties which I have overcome, and which I reckon for so many won Battails on my side. Neither will I forbear to say; That I think, It's only necessary for me to win two or three more such, wholly to perfect my design. And that I am not so old, but according to the ordinary course of Nature, I may have time enough to effect it. But I beleeve I am so much the more obliged to husband the rest of my time, as I have more hopes to employ it well; without doubt, I should have divers occasions of impeding it, should I publish the grounds of my Physicks. For although they are almost all so evident, that to beleeve them, it's needfull onely to understand them; and that there is none whereof I think my self unable to give demonstration. Yet because it's impossible that they should agree with all the severall opinions of other men, I foresee I should often be diverted by the opposition they would occasion.
It may be objected, These oppositions might be profitable, as well to make me know my faults, as if any thing of mine were good to make others by that means come to a better understanding thereof; and as many may see more then one man, beginning from this time to make use of my grounds, they might also help me with their invention. But although I know my self extremely subject to fail, and do never almost trust my first thoughts; yet the experience I have of the objections which may be made unto me, hinder me from hoping for any profit from them; For I have often tried the judgments as well of those whom I esteem'd my friends, as of others whom I thought indifferent, and even also of some, whose malignity and envie did sufficiently discover what the affection of my friends might hide. But it seldom happened that any thing was objected against me, which I had not altogether foreseen, unless it were very remote from my Subject: So that I never almost met with any Censurer of my opinions, that seemed unto me either less rigorous, or less equitable then my self. Neither did I ever observe, that by the disputations practiced in the Schools any Truth which was formerly unknown, was ever discovered. For whilest every one seeks to overcome, men strive more to maintain probabilities, then to weigh the reasons on both sides; and those who for a long time have been good Advocates, are not therefore the better Judges afterwards.
As for the benefit which others may receive from the communication of my thoughts, it cannot also be very great, forasmuch as I have not yet perfected them, but that it is necessary to add many things thereunto, before a usefull application can be made of them. And I think I may say without vanity, That if there be any one capable thereof, it must be my self, rather then any other. Not but that there may be divers wits in the world incomparably better then mine; but because men cannot so well conceive a thing and make it their own, when they learn it of another, as when they invent it themselves: which is so true in this Subject, that although I have often explain'd some of my opinions to very understanding men, and who, whilest I spake to them, seem'd very distinctly to conceive them; yet when they repeated them, I observ'd, that they chang'd them almost always in such a manner, that I could no longer own them for mine. Upon which occasion, I shall gladly here desire those who come after me, never to beleeve those things which may be delivered to them for mine, when I have not published them my self. And I do not at all wonder at the extravagancies which are attributed to all those ancient Philosophers, whose Writings we have not; neither do I thereby judge, that their thoughts were very irrationall, seeing they were the best Wits of their time; but onely that they have been ill convey'd to us: as it appears also, that never any of their followers surpass'd them. And I assure my self, that the most passionate of those, who now follow Aristotle, would beleeve himself happy, had he but as much knowledge of Nature as he had, although it were on condition that he never might have more: They are like the ivie, which seeks to climb no higher then the trees which support it, and ever after tends downwards again when it hath attain'd to the height thereof: for, me thinks also, that such men sink downwards; that is to say, render themselves in some manner lesse knowing, then if they did abstain from studying; who being not content to know all which is intelligibly set down in their Authour, will besides that, finde out the solution of divers difficulties of which he says nothing, and perhaps never thought of them: yet their way of Philosophy is very fit for those who have but mean capacities: For the obscurity of the distinctions and principles which they use causeth them to speak of all things as boldly, as if they knew them, and maintain all which they say, against the most subtill and most able; so that there is no means left to convince them. Wherein they seem like to a blinde man, who, to fight without disadvantage against one that sees, should challenge him down into the bottom of a very dark cellar: And I may say, that it is these mens interest, that I should abstain from publishing the principles of the Philosophy I use, for being most simple and most evident, as they are, I should even do the same in publishing of them, as if I opened some windows, to let the day into this cellar, into which they go down to fight. But even the best Wits have no reason to wish for the knowledge of them: for if they will be able to speak of all things, and acquire the reputation of being learned, they will easily attain to it by contenting themselves with probability, which without much trouble may be found in all kinde of matters; then in seeking the Truth, which discovers it self but by little and little, in some few things; and which, when we are to speak of others, oblige us freely to confesse our ignorance of them. But if they prefer the knowledge of some few truths to the vanity of seeming to be ignorant of nothing, as without doubt they ought to do, and will undertake a designe like mine, I need not tell them any more for this purpose, but what I have already said in this Discourse: For if they have a capacity to advance farther then I have done, they may with greater consequence finde out of themselves whatsoever I think I have found; Forasmuch as having never examined any thing but by order, it's certain, that what remains yet for me to discover, is in it self more difficult and more hid, then what I have already here before met with; and they would receive much less satisfaction in learning it from me, then from themselves. Besides that, the habit which they would get by seeking first of all the easie things, and passing by degrees to others more difficult, will be more usefull to them, then all my instructions. As I for my part am perswaded, that had I been taught from my youth all the Truths whose demonstrations I have discovered since, and had taken no pains to learn them, perhaps I should never have known any other, or at least, I should never have acquired that habit, and that faculty which I think I have, still to finde out new ones, as I apply my self to the search of them. And in a word, if there be in the world any work which cannot be so well ended by any other, as by the same who began it, it's that which I am now about.
It's true, That one man will not be sufficient to make all the experiments which may conduce thereunto: But withall, he cannot profitably imploy other hands then his own, unlesse it be those of Artists, or others whom he hires, and whom the hope of profit (which is a very powerfull motive) might cause exactly to do all those things he should appoint them: For as for voluntary persons, who by curiosity or a desire to learn, would perhaps offer themselves to his help, besides that commonly they promise more then they perform, and make onely fair propositions, whereof none ever succeeds, they would infallibly be paid by the solution of some difficulties, or at least by complements and unprofitable entertainments, which could not cost him so little of his time, but he would be a loser thereby. And for the Experiments which others have already made, although they would even communicate them to him (which those who call them Secrets would never do,) they are for the most part composed of so many circumstances, or superfluous ingredients, that it would be very hard for him to decypher the truth of them: Besides, he would find them all so ill exprest, or else so false, by reason that those who made them have laboured to make them appear conformable to their principles; that if there were any which served their turn, they could not at least be worth the while which must be imployed in the choice of them. So that, if there were any in the world that were certainly known to be capable of finding out the greatest things, and the most profitable for the Publick which could be, and that other men would therefore labour alwayes to assist him to accomplish his Designes; I do not conceive that they could do more for him, then furnish the expence of the experiments whereof he stood in need; and besides, take care only that he may not be by any body hindred of his time. But besides that, I do not presume so much of my Self, as to promise any thing extraordinary, neither do I feed my self with such vain hopes, as to imagine that the Publick should much interesse it self in my designes; I have not so base a minde, as to accept of any favour whatsoever, which might be thought I had not deserved.
All these considerations joyned together, were the cause three years since why I would not divulge the Treatise I had in hand; and which is more, that I resolved to publish none whilest I lived, which might be so general, as that the Grounds of my Philosophy might be understood thereby. But since, there hath been two other reasons have obliged me to put forth some particular Essays, and to give the Publick some account of my Actions and Designes. The first was, that if I failed therein, divers who knew the intention I formerly had to print some of my Writings, might imagine that the causes for which I forbore it, might be more to my disadvantage then they are. For although I do not affect glory in excess; or even, (if I may so speak) that I hate it, as far as I judge it contrary to my rest, which I esteem above all things: Yet also did I never seek to hide my actions as crimes, neither have I been very wary to keep my self unknown; as well because I thought I might wrong my self, as that it might in some manner disquiet me, which would again have been contrary to the perfect repose of my minde which I seek. And because having alwayes kept my self indifferent, caring not whether I were known or no, I could not chuse but get some kinde of reputation, I thought that I ought to do my best to hinder it at least from being ill. The other reason which obliged me to write this, is, that observing every day more and more the designe I have to instruct my self, retarded by reason of an infinite number of experiments which are needful to me, and which its impossible for me to make without the help of others; although I do not so much flatter my self, as to hope that the Publick, shares much in my concernments; yet will I not also be so much wanting to my self, as to give any cause to those who shall survive me, to reproach this, one day to me, That I could have left them divers things far beyond what I have done, had I not too much neglected to make them understand wherein they might contribute to my designe.
And I thought it easie for me to choose some matters, which being not subject to many Controversies, nor obliging me to declare any more of my Principles then I would willingly, would neverthelesse expresse clearly enough, what my abilities or defects are in the Sciences. Wherein I cannot say whether I have succeeded or no; neither will I prevent the judgment of any man by speaking of my own Writings: but I should be glad they might be examin'd; and to that end I beseech all those who have any objections to make, to take the pains to send them to my Stationer, that I being advertised by him, may endeavour at the same time to adjoyn my Answer thereunto: and by that means, the Reader seeing both the one and the other, may the more easily judge of the Truth. For I promise, that I will never make any long Answers, but only very freely confesse my own faults, if I find them; or if I cannot discover them, plainly say what I shal think requisite in defence of what I have writ, without adding the explanation of any new matter, that I may not endlesly engage my self out of one into another.
Now if there be any whereof I have spoken in the beginning, of the Opticks and of the Meteors, which at first jarr, by reason that I call them Suppositions, and that I seem not willing to prove them; let a man have but the patience to read the whole attentively, and I hope he will rest satisfied: For (me thinks) the reasons follow each other so closely, that as the later are demonstrated by the former, which are their Causes; the former are reciprocally proved by the later, which are their Effects. And no man can imagine that I herein commit the fault which the Logicians call a Circle; for experience rendring the greatest part of these effects most certain, the causes whence I deduce them serve not so much to prove, as to explain them; but on the contrary, they are those which are proved by them. Neither named I them Suppositions, that it might be known that I conceive my self able to deduce them from those first Truths which I have before discovered: But that I would not expresly do it to crosse certain spirits, who imagine that they know in a day al what another may have thought in twenty yeers, as soon as he hath told them but two or three words; and who are so much the more subject to erre, and less capable of the Truth, (as they are more quick and penetrating) from taking occasion of erecting some extravagant Philosophy on what they may beleeve to be my Principles, and lest the fault should be attributed to me. For as for those opinions which are wholly mine, I excuse them not as being new, because that if the reasons of them be seriously considered, I assure my self, they will be found so plain, and so agreeable to common sense, that they will seem less extraordinary and strange then any other which may be held on the same Subjects. Neither do I boast that I am the first Inventor of any of them; but of this indeed, that I never admitted any of them, neither because they had, or had not been said by others, but only because Reason perswaded me to them.
If Mechanicks cannot so soon put in practise the Invention which is set forth in the Opticks, I beleeve that therefore men ought not to condemn it; forasmuch as skill and practice are necessary for the making and compleating the Machines I have described; so that no should be wanting. I should no less wonder if they should succeed at first triall, then if a man should learn in a day to play excellently well on a Lute, by having an exact piece set before him. And if I write in French, which is the language of my Country, rather then in Latin, which is that of my Tutors, 'tis because I hope such who use their meer naturall reason, wil better judge of my opinions, then those who only beleeve in old Books. And for those who joyn a right understanding with study, (who I only wish for my Judges) I assure my self, they will not be so partiall to the Latin, as to refuse to read my reasons because I expresse them in a vulgar tongue.
To conclude, I will not speak here in particular of the progresse I hoped to make hereafter in Learning; Nor engage my self by any promise to the Publick, which I am not certain to perform. But I shall onely say, That I am resolved to employ the remainder of my life in no other thing but the study to acquire some such knowledge of Nature as may furnish us with more certain rules in Physick then we hitherto have had: And that my inclination drives me so strongly from all other kind of designes, chiefly from those which cannot be profitable to any, but by prejudicing others; that if any occasion obliged me to spend my time therein, I should beleeve I should never succeed therein: which I here declare, though I well know it conduceth not to make me considerable in the world; neither is it my ambition to be so. And I shall esteem my self always more obliged to those by whose favour I shal without disturbance enjoy my ease, then to them who should proffer me the most honourable imployment of the earth.