Laftly, To find out the Greatnefs of Inequality betwixt Relations, proceeding, one from a Com- pounded Reafon, or from the Relation of a Relation of 1 2 to 3, and 3 to 1; and the other from a Compounded Reafon, or from the Relation of a Relation, as of 8 to 2, and 2 to j; we muft follow the fame Method. Fitft, The Magnitude of the Reafon of 12 to 3, is marked by 4 $ 4 being the Quotient of the Reafon of 12 to 3, and 3 the Quotient of that of 3 to 1; and the Quotient of Reafon of the Quotients 4 and 3, is. 4- Secondly, The Quotient of 8 to 2, is 4 -, and that of 2 to 1, is 2 •, and the Quotient of the Quotients 4 and 2, is 2: So that the Inequa- lity betwixt the Relations, that here refult from the Relations of the Relations, is the Difference betwixt 4 and 2, that is to fay, f: And therefore add 7 to the Relation of the Reafons 12 to 3, and no 1 5 or fubtraft them from the Relations of the other Reafons, 8 to 2, and 2 to i; and you'll make even thofe Relations of Relations, and produce a Compounded Proportion. Thus we may ufe Additions and Subtractions to equal Magnitudes, and their Relations both fimple and compounded -, and likewife to frame an accurate Idea of the Greatnefs of their Inequality.
True it is, that we ufe alfo Multiplications and Divifions, both fimple and compounded; but they are only Compound Additions and Subtractions. To multiply 4 by 3, is to make as many Additions of 4, as 3 contains Unites; or to find a Number that has the fame Relation to 4, as 3 with the Unite. To divide 12 by 4, is to fubtract 4 from 12 as often as poffible; that is, to find a Relation to the Unite, that may be equal to that of 12 to 4 •, for 3, which is the Quoti- ent, has the fame Relation to 1, as 12 has to 4. The Extractions of the Square, Cubick, and other Roots, are but Divifions, to find out one, two, or three mean proportional Magnitudes.
'Tis evident, that the Mind of Man is fo narrow, his Memory fo unfaithful, and his Imagination fo lhallow, that, without the ufe of Figures, and Writing, and the Skill of Arithmetick, it would be impomble to make the neceffary Operations, to know the Inequality of Magnitudes, and their Relations, elpecially where many Numbers muft be added or fiibtracted •, or, which is the fame thing, when thofe Numbers are very great, and can be added but by Parts: For fome of them would ftill be forgotten, t,here being no Imagination fb extended, as to add together very great Fractions, as 44* j] -1-7714444 ••> oi4 to fubtract one from the other.
Multiplication, Divifion, and the Extraction of Roots in entire Numbers, are infinitely more! puzling, than fimple Additions or Subtractions. The Mind alone, without the help of Arith- metick, is too fhallow and weak to make fuch Operations •, and it would be to no purpofe to infift upon the Proofs of it.
Notwithstanding, Analyticks, or Algebra, is ftill more excellent than Arithmetick •, becaufe ic lefs divides the Capacity of the Mind, and abridges the Ideas in the molt fimple and eafie manned imaginable. What may be done in a long time by Arithmetick, is performed in a moment by Algebra, without puzling the Mind by the Change of Cyphers^ and the Tedioufnefs of Operati- ons. And laftly, There are knowable Things, and neceffary to be known, of which Arithmetick alone cannot afford the Knowledge; but I believe not that there is any Thing ufeful, and which may be certainly and exactly known, but it may be found out by an Arithmetical and Algebraical Method. So that thofe two Sciences are the Foundation of all others, and help us to the true Means to acquire all thofe that are accurate, becaufe the Capacity of the Mind cannot be better managed titan it is by Arithmetick, and efpecially by Algebra.
N T H F to F. Malebranche Concerning Book VI.
THE Of 'the Rules that are to be obferved in the Search after 1 ruth.
% TAving explain'd the means how to improve the Attention and Extenfion of the Mind, by whicji alone it may acquire a greater perfection, that is, become more enlightned, fagaci- ous and piercing •, it is time to fet down thofe Rules, the Oblervation whereof is abfo- lutely neceflary to refolve any Queftion whatfoever. I fhall infift long upon it, and en- deavour to explain them by feveral Inftances; that their neceflity may be better known, and the Mind accuftomed to make ufe of them; it being not fo difficult or neceflary, to know them theo- retically, as to put them in Practice.
Let none expect here very extrordinary, furprizing and abftrule things: For on the contrary, that thofe Rules may be good, they muft be very fimple, natural and few, very plain and intel- ligible, and depending on each other •, in fhort, fuch as may lead our Mind, and rule our Atten- tion, without diftrafting either: For Experience mews that the Logick o?Ariftotle is of no great ufe, becaufe it takes up the Mind too much, and difturbs the Attention it ought to give to the Subjects of its Enquiry. Let then thofe Lovers of Myfteries and rare Inventions lay afide for a while that capricious humour, and confider, as attentively as they can, whether the Rules we (hall pre- fcribe are fufficient to preferve Evidence in the Preceptions of the Mind, and to difcover the moft hidden Truths. Unlefs they fufFer themfelves to be unjuftly prejudiced againft thofe Rules, by the fimplicity and eafinefs of the fame, I hope that the great ufe which may be made of them,' as we inall mew hereafter, will convince them, that the moft clear and fimple Principles are the moft pregnant and fecund, and that rare and difficult things are not always fo ufeful as our fruit- lefs Curiofity endeavours to perfuade us* The Principle of all thofe Rules is, that we muft always preferve Evidence in our Reafonings, to difcover Truth without Fear, and danger of being miftaken. From that Principle follows this general Rule, that reipe£ts the SubjecT: of our Studies: We ought only to Reafon upon fuch things^ whereof we have clear and diftinll Ideas; and by a neceflary conlequence, we muft ft ill begin with the moft fimple and eafie Subjecls, and infift long upon them, before we undertake the Enquiry into fuch as are more compofed and difficult.
The Rules that concern the Method to be taken in refolving Queftions, depend likewife on the fame Principle; and the firft of thofe Rules is, that we muft very diftintfly conceive the State of the Queftion propofed to be refoMd: that is, have Ideas of the Terms fo diftinft, as that we may com- pare them together, and difcover the Relations which we look for.
When thole Relations cannot be found out by an immediate comparifon of their Ideas, then the fecond Rule is, that we muft try by an Effay of Thought to difcover one, or feveral intermediate Ideas, that may be a means or common meafure to difcover the Relations that are betwixt thofe things. A fpecial care is to be taken that thofe Ideas be the more clear and diftinft, as the Relations we endeavour to difcover are more nicely exacl: and numerous.
When the Queftions are very difficult, and require a long Examination, the third Rule is, that we muft carefully take off from the Subjetf to be confider 'd, all things zvhqfe Examination is not needful to the pif cove ry of the Truth we are in queft of. For the Capacity of the Mind muft not be vainly fliar'd and divided, but its ftrength muft only be employed in fueh things as may en- lighten it -, fo that all thole things which are to be laid afide, are fuch as concern not the Quefti- on, and which, when taken off, leave it whole and entire.
When the Queftioii is thus brought within the leaft compafs, the fourth Rule is, to divide the' Subject of our Meditations into "Parts, and confider them one after the other in a natural order -, be- ginning with the moft fimple, or thofe that contain the leaft number of Relations, and never medling with the more compofed, before the moft fimple are diftintfly known, and become familiar.
When Chap. II. The Search after Truth. 'k t When they are become familiar by Meditation, the filth Rule is, to abridge Ideas and diffojfc them in the Imagination, or write them upon Paper, that they may no longer clog and Jill up the Capacity of the Mind. Though that Rule be always ufetul, yet ris not of abfolute naceffity^ un- lets it be in very intricate Queitions, that require a great extent of Mind, ( lor the Mind is only enlarg'd by the abridgment of Ideas). But the tile of that Rule and the following, is belt known by Algebra.
The Ideas of all the things that neceflafily require Examination, being clear, familiar, abridg'd, and difpoied and ranged in good order in the Imagination, or written upon Paper, the fixtlr Rule is, to compare them all by the Rules of Complications, one with the other alternately, either by the View oj the Mind alone, or by the Motion of the Imagination, attended with the View of the Mind, or by the Calculation of the Pen joined to the attentwn.of '.he Mind and Imagination.
li amongit all the Relations that refult from thole Comparifons, you find not that which you 'enquire alter; then take off again all the Relations that are not fubjervient to refolve the- ^lejiion, ?ua/:c the others familiar, abridge them, pofiure and difpofe them in the Imagination, or write them- upon Paper, compare them together by the Rules of Complications, and then fee whether the co.iipojei Relation that is looked for, a one of the compofed Relations that refult from thofe new Corn- far ij ens.
ir npne of thofe new difcover'd Relations contain the Solution of the Queftion, then take off again ihoje that are ufelefs, make the other familiar, &c. [_That is, doe the fame over and over, a..d 1 continuing thus, you mail difcover the Truth or Relation you enquire after, how compofed ioever it may be; provided you can extend the Capacity of your Mind to it, by abridging your Iaeas, and Hill in all your Operations having before your Eyes the Scope you aim at. For 'tis the continual aid. fteady view of the Queftion which mull regulate all the. advances of the Mind -, fiuce we mould always know whither we are going.
We mult above all take care not to fatisfie our felves with fome glimpfe or likelyhood; but begin anew io often the Comparifons that are conducible to difcover the Truths enquired after, mat we may not withold our Affent to it, without feeling the fecret Lalhes and Reproofs of our internal Mailer that Aniw'ers bur Queitions, that is, the Application of our Mind, and the De- nies of our Heart. Then will that Truth ferve as an infallible Principle, to proceed in the Ac- quiikion of Sciences.
:h.ii the Kules we have given are not neceflary in all forts of Queftions: for the firft Rule is fufc ficunt hi thole that are ealie: and we need but in fome others the firft and fecond. In (hort, fince we mult make uie of thole Rules, 'till we have diicover'd the Truth we feek for; it follows, mat the more difficult the Queitions are^ the greater muft the number of thole Rules be which we mi -it put in -practice.
Tiiou Rules are not very numerous, but very natural, as depending upon each other, and may be maae io familiar as to fall of themfelves into the Mind, as often as fhall be requifite. In ffiort, they can rule the Attention of the Mind without dividing it, which is in great part what we could defiie • but. they look io inconfiderable in themfelves, that to make them more recommendable, it s iieceiTary to (hew that the Philofophers are fallen into a great many Errours, and Extrava- ganc.es, by not obierving lb much as the two firft, which are the chief and eafieft of all; whereas Des v j.rte-s, by their uie, has difcover'd all thofe great and fruitful Truths, which are to be learn'd in nis Works.
CHAP. II.
CHAP. II.
Of the general Rule that concerns the SubjeB of our Studies: That School- Philojophers obferve it noty which is the Cauje of federal Errours in their Fhyfickg.
THE firft of thefe Rules, and which refpeQs the Subject of our Studies, teaches, that we muft not argue, except from clear Ideas; whence it follows, that to ftudy methodically, we rnuft begin with things moft fimple and ealie to be underftood, and infill long upon them, before We undertake to enquire after the more compofed and difficult.
Every one will eafily grant the* neceflity of that general Rule; plainly feeing, that he walks in the dark, who reafons upon obfeure Ideas, and uncertain Principles. But 'twill be matter of fur- prize to hear us affirm, that it is hardly ever obferved; and that the greateft part of thofe Scien- ces, which ftill at this day flulTi the Pride of fome falfe Pretenders to Science, are only grounded upon fuch Ideas, as are either too confufed, or too general, to be conducible to the finding out bf Truth.
Ariflotle, who fo juftly deferves the Quality of Prince of fuch Philofophers, (as being die Fa- ther of that Philofophy which they fo ftudioufly cultivate,) reafons very feldom upon other Ideas, than fach as are confufed and fenfible, and upon others that are general, undetermin'd, and repre- senting nothing particular to the Mind. For the ordinary Expreflions of that Philofopher are lb perplexed, as to reprefent only to the Senfes and Imagination, the confufed Sentiments we have of fenfible things h or to make his Difciples fpeak in iiich a rambling and indeterminate manner, as ^2 K NIaleeranche' ConteTning Book VI.
as hOl to underftand themfelves. Moll of his Works, but efpecially his Eight Books of Phyficks,, on which are as many different Commentators as there are ProfefTors of Philofophy, are a mere Logical Tattle, where hej talks much, and fays nothing: Not that his Stile is too copious and diftufed, but becaufe he has a particular Talent at being fuccincf, and laying nothing but Words. In his other Works he makes not luch frequent ufe of his loofe and general Terms ^ but thofe he employs raife only the confuted Ideas of the Senfes:, by which Ideas he pretends, in his Problems, and el'fewhere, to relblve in two Words -an infinite Number of Queftions, of which it may be de- monllrated that they are altogether infbluble.
But that my Meaning may be better underftood, what I have proved in other Places mull here be remembred, viz. That all the Terms that excite nothing but fenfible Ideas, are equivocal ^ nay, and what's to be well obferv'd, Equivocal from Errour and Ignorance, which mult needs caufe an infinite number of Delufions.
The Word Riim is equivocal, fignifying ah Animal that ruminates, and a Conftellation into which the Sun enters at Spring h but that feldom caufes any Miftake: For he muft be an Allrologer with a Witnefs, who fhould imagine any Relation betwixt thole two Things, and believe, for in- llance, that we are fubject at that time to vomit up the Medicines that we take, becaufe the Ram is a ruminating Beaft. But as to the Terms of fenfible Ideas, but few acknowledge them for Equivocal. Ariftoilc and the Ancient Thilofopheis did not fo much as dream on't ^ which will be agreed to by any one that has read any of their Books, and diftin£tly knows the Caufe why thole Words are liable to Equivocation* For nothing is more evident, than that the Philofophers Opi- nion, as to that Matter, was quite contrary to the Truth.
For inftance: When they lay, that Fire is hot, Grafs green, Sugar fweet $ they underfland, juft as Children, and the vulgar of Men, that Fire contains in it what they feel when they warm them- felves ^ that Grafs has painted upon it the Colours they fee -, that Sugar is endued with that Sweetnefs they talle when they eat it ^ and fo as to all other vilible and fenfible Qualities -, which cannot be denied by thofe that have read their Writings. They talk of fenfible Qualities as of Senfations; they take Heat for Motion. And thus, by the Equivocation of Terms, they confound the Modes of Exiftence peculiar to Bodies, with the Modifications of the Soul.
'TLs no longer liner than Des Cartes's time, that to thofe confuted and indeterminate Quefti- ons, Whether Fire is hot, Grafs green, and Sugar fweet, Cfc. we ufe to anfwer by diftinguifh- ing the Equivocation of fenfible Terms that exprefs them. If by Heat, Colour, and Savour, you underltand fuch arid fuch Difpofitions of Parts, or Motion of infenfible Particles, then Fire is hot, Grais green, and Sugar fweet. But if by Heat, and other Qualities, you underftand what I feel when near the Fire, what I fee when I fee Grafs, &c. Fire is not hot, nor Grafs green, &c. For the Heat I feel, and the Colours I fee, are only in the Soul, as has been proved in the Firft Book. But as Men commonly fuppole, that what they feel is the fame with that which is in the Object i fo they believe they are in the right, when they judge of the Qualities of Objects by their own Senlations: And thus they hardly fay two Words without fpeaking a Falfehood, and never fay any thing upon that Matter, but what is obfeure and confufed j and that for the feveral following Reafons.
Firft, Becaufe all Men have not the fame Senfations of the fame Objefts, nor even the fame Man in different Times, or when different Parts of his Body are affected by them. What i3 fweet to one, is bitter to another ^ what is hot to one, is cold to another; what feems hot to a Man when he is cold, feels cold to himfelf when he is hot, or when other Parts of his Body are affe&ed. Water, that feels warm to the Hands, will feem cold if we wafh with it any Part near the Heart. Salt, that is favoury to the Tongue, is pricking and fmarting to a Wound. Su- gar is fweet, and Aloes very bitter to t,he Tongue; but nothing is either fweet or bitter to the other Senfes: So that when we fay, a Thing is cold, fweet, bitter, £>V. that fame has no certain Signification.'
Secondly, Becaufe different Obje£ls can caufe the fame Senfation. Plaifter, Bread, Snow, Su- gar, Salt, &c. are of the fame Colour; and yet their Whitenefs is different, if we judge of "erri otherwife than by the Senfes: And therefore when we fay, that Meal is white, we fay not any thing diltinctly fignificative.
The third Realbn is, Becaufe fuch Qualities Of Bodies as occafion Senfations altogether diffe- rent, are however almolt the fame -} whereas fuch. as excite very near the fame Senfation, are often very different. The Qualities of Sweetnefs and Bitternefs differ but little in Objects i whereas the Senie of Sweet effentially differs from that of Bitter. The Motions that caufe Smart and Tickling, differ but in more or lefs ^ and yet the Senlations of Tickling and Smart are effentially different. On the contrary, the Sharpnefs of Fruit differs not fo much from Bitternefs, as Sweet* nels does 3 however, that fharp Quality is the fartheft from Bitternefs that poflibly can be: For, a Fruit that is fharp for being unripe, mult undergo a great many Changes, before it grows bitter horn Rottennefs, of too much Ripenefs. When Fruits are ripe, they talle fweet -, and bitter, when over-ripe: Bitternefs and Sweetnefs therefore in Fruits differ but in degree of more and .lefs; which may lie the Realbn why they feem fweet to fome Perfons, whilft they tafte bitter to others: Nay, there are thofe to whom Aloes feem as fweet as Honey. The fame may be faid of all fenfible Ideas j fo that the Words Sweet, Bitter, Salt, Sovvre, Acid, &c. Red, Green, Yellow, Cfo of fuch and fuch a Smell, Savour, Colour, &c. are all equivocal, and raife no clear and diltin£l Idea in the Mind. However, School-Philofophers, and the vulgar part of Men, judge of all the fenfible Qualities of Bodies by the Senlations they receive from them.
Nor Chap. II. The Search afier Truth. Jj Nor do the Philofophers only judge of thefe. fenfible Qualities by their own Senfjitibfis of them; but alio iudge of the Things themielves, from the Judgments they have pafs'd about fen- fible Qualities/. For, from their having had Senfatious of certain Qualities^ eiTentially different, they judge that there is a Generation of new Forms, producing thofe fantaftick Differences^ Wheat appears yellow, hard, &c. Meal, white, foft, &c.. Thence, upon the Teftimony of their Eyes and Hands, they infer, That thofe Bodies are, eflentially different, unlefs they chance to. think on the Manner of the Tranfmutation of Wheat into. Flower: For Meal is nothing but bruifed and ground Corn; as Fire is only divided and agitated Wood ■, as Allies are but the grolTeif Parts of the divided Wood without Agitation; as Glafs is but Allies, whole Particles have been, polilhed and rounded by the Attrition caus'd by the Fire: And fo in other Tranfmutations of Tis therefore evident, that fenfible Words and Ideas are altogether unserviceable to a juft lta- ting, and clear reiblving of ^ueftions -, that is, to the Difcoyery of Truth. Yet there are no Qffe- ftions, how intricate foever they may be, by the equivocal Terms of the Senfes, but Ariftotle, and molt part of other Philofophers, pretend to refolve them in their Books, without the forego- ing DiftincYions, and without confidering that they are. equivocal by Errour and Ignorance.
If, for example, thofe Perfons who have employed the beft part of their Life in reading Anc;H ent Philofophers and Phyficians, and have wholly imbib'd their Spirit and Opinions, are ask'd whether Water be wet, whether Fire be dry, Wine hot, the Blood of Fifties cold, Water rawer than Wine, Gold perfeSter than Mercury •, whether Plants and Beafts have Souls -, and a thoulaud like undetermin'd ^jicftions; they raihly anfwer, by confulting only the Impreltions of Objects upon their Senfes, or the Tracks the 'reading of Authors has left upon their Memory. They never think thofe Terms are equivocal; 'tis a Wonder to them they Ihould need a Defini- tion'^ and they cannot endure thofe that endeavour to let 'em underftand,- that their Procedure is too quick, and that they are feduced by their Senfes; and though they are never at a lofs for Diftinciions to perplex the moil evident Things, yet in thefe ^iieftions, in which Equivocation • needs fo much to be removed, they find nothing to diftinguilh.
If we coniider, that molt of the Qiceftions of Philofophers and Phyficians contain ibme equi- vocal Terms, like to thofe that have been fpoken of ^ we lhall not doubt, but that thofe Learned ' Gentlemen, that could not define them, were unable to fay any Thing folid and real, in the bulky Volumes they have compos'd: Which is, in a manner, fufficient to overthrow molt of the Opi- nions of the Ancients. It is not fo with Des Cartes; he perfectly knew how to diftinguilh thofe Things: He ne'er refolves any Queftion by fenfible Ideas -, and whoever lhall be at the pains to read him, lliall fee, that he clearly, evidently, and almbft ever demonftratively, explains the chief Operations of Nature by the fole and diftinct Ideas of Extenlion, Figures, and Motion.
The fecond fort of equivocal Words, that is much in requeft amongft Philofophers, contains all thofe general Terms of Logick by which any Thing may be eafily explain'd, without fo much as knowing it. Ariftotle was the Man that made the moft of it; his Books are full of nothing elle, and fome are but a mere Logick: He propofes and refolves all Things by the fpecious Words of Genus, Species, Att, Power, Nature, Form, Faculty, ^jia/ity^ Caufa per fe, Caufa per acci- dens: His Followers can hardly underftand that thofe Words fignifie Nothing,- and that one is not more learned than he was, when he has heard, that Fire diflolves Metals by its diflblving Faculty -, that a Man digefts not, becaufe his Stomach is weak, or becaufe his Concoffive Faculty does not operate as it Ihould do.
I grant, that thofe who ufe fuch general Terms and Ideas for the Explication of all Things, commonly fall not into fo many Errours, as thofe that only employ fuch Words as raife the con- fuied Ideas of the Senfes. The School-Philofophers are not fo liable to be deceived, as fome opinionative and dogmatical Phyficians, who build Syftems upon Experiments, the Reafons of which are unknown to them -, becaufe the School-men talk fo generally, that they do not venture much out of their Depth.
Fire heats, dries, hardens, and foftens, becaufe it has the Faculty of producing thofe Effects: Sena purges by its purgative Quality: Bread nourilhes by its nutritious Quality. Thefe Propofi- tions are not liable to miftake; for a Quality is that which denominates a Thing by fuch a Name; Mafter Ariftotle's Definition is undeniable: But he ipeaks true only becaufe he fays no- thing ■, and if his rambling, loofe, and indefinite Notions engage not into Errour, at leaft they are wholly unferviceable to the Difcovery of Truth.
For, though we know that there is in Fire a fubftantial Form, attended with a Million of Fa- culties, like to that of heating, dilating, melting Gold, Silver, and other Metals, lightening, burning, roafting; the Idea of that fubftantial Form, with all its Faculties of producing Heat, Fluidity, Rarefaction, will not help me to refolve this Queftion, Why Fire hardens Clay, and fof- tens Wax? There being no Connection betwixt the Ideas of Hardnefs in Clay and Softnefs in Wax, and thofe of a fubftantial Form in Fire, and its Faculties of Rarefaction, Fluidity, &c. The fame may be faid of all general Ideas; which are utterly infufficient for reiblving any Queftion.
But when I know that Fire is nothing elfe but divided Wood, whofe Parts are in a continual Agitation, by which alone it raifes in me the Senfation of Heat -, and that the Softnefs of Clay confifts in a Mixture of Water and Earth =, thofe Ideas being not general and confufed, but par- ticular and diftinct, it will not be difficult to perceive that the Heat of Fire muft harden Clay, nothing being ealier to conceive, than that one Body may move another, if it meet with it, being it felt' in Motion. We likewife eafily perceive, that fince the Heat we feel near the Fire is caufed O by' ej4 F. Malebranche Concerning Book VI: by the Motion of the invifible Particles of Wood ftriking againft our Hands, Face, &c. if we -ex- pofe Clay to the Heat of Fire, the Particles of Water, that are mixed with thole of Earth, be- ing more thin and difunited, and confequently more agitated by the A£tion and Impulfe of the fiery Corpufcles, than the grofs Particles of Earth, mult be feparated and expelled, and the other remain dry and hard. We (hall perceive with the fame Evidence, that Fire muft produce a quire contrary EffeO: upon Wax, if we know that it is compofed of Particles that are branched, and almoft of the fame Bulk. Thus may particular Ideas be fubfervient to the Enquiry after Truth, whilft loofe and undeterminate Notions are not only altogether unferviceable, but alfo infenfibly engage us into Errour.
For, thefe Phil ofophers are not content to make ufe of thofe general Terms, and uncertain Ideas which anfwer to them ^ they moreover pretend,_that thofe Words fignifie fome particular Beings •, they give out, that there is a Subftance diftinguiihed from Matter, which is the Form of it ^ and withal, an infinite Number of little Beings, really dihinguiiTied from that Matter and Form, of which they fuppofe as many as they have different Senfations of Bodies, or as thofe Bodies are iuppofed to produce different Effetts.