Tertia via Walgrave

7/28/2019 Tertia via Walgrave

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J. H . W A L G R A V E O.P.TERTIA VIA

The difjicultyWhen reading the text of the Third W ay superficially, one might

get the impression that this third way is not so problematic as some.'of the other ways , for instance, as the fou r th or the f i f th . This followsfrom the man n er in which many authors speak about the fivew ays . For us, however, the third way remains, in a sense, the mostdifficult one, for there is a rather apparen t gap in the a r g u m e n t . It saysthat in the succession in time of beings, which cease to exist by passingaway and, therefore , by generat ion are the occasion for the coming-into-being of other things, and these are the possibilia esse et non esse ,one cannot infinitely go back , although th e chain can go on indefinitely.The principie that in the succession of the possibilia one cannot infini telygo backward is logically necessary for the conclusin: Si igitur omnias un t possibilia non esse, aliquando nihi l fu i t in rebus . However, thisis affirmed, but not proven. Is it really so evident that the chain ofgenerat ion and corrupt ion cannot inf in i te ly go back , as it can go forwardindefinitely? For here there is no question of a series of causes per se, asin the prima and secunda va, but of a series of causes per accidens. Ina series of causes per se th e immediate or ultmate part icular cause canonly exercise hic et nunc it s causali ty by v i r tue of the causality, whichcomes for th from the first universal cause. In case there is no f irst cause ,or in case it does not work, the last one cannot work and there wouldbe no effec t , which, never the less , we observe with our own eyes . B u tthis does not apply to a series per accidens: each part icu lar cause in theseries produces th e next one in the success ion of t ime . The concept ofa series of causes , in which the hen produces th e egg, and the egg a hen,does not imply there must have been a first lien as the starting pointof th e series.After having drawn at tent ion to this gap in the logic of the argu-ment , we m u s t now reconst ruct in its ent i re ty the a rg u men t as it ispresented by St . Thomas .


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66 T E R T I VI A

Th e point of departure Tertia via sum tur ex possibili et necessario . Unlike th e primavia, which starts from th e concep t of change , "prima et manifest iorvi a s u m i t u r ex motu" , now the point of departure is dual: ex pos-sibili et necessario . The reason is that when something that is neces-sary ha s been shown to exist in reali ty, one has not yet proven tha tG od exists. Th e conclusin that God exists follows formally from th eaffirmat ion that in the universe there are not only possibilia but alsonecessaria.Therefore there are two stages in the argument: a fi rs t prepara tory

stage, in which it is shown that the world of possibilia implies as a m a t t e rof fact the existence of necessaria; and a next , decisive stage in which itis shown that the existence of the necessaria among things implies ofnecessity the existence of God.Fundamental concepts

In order to understand this argument first cer ta in notions and dis-t inct ions m u s t be made clear.In the first place a very general observation: the philosophy ofSt . Thornas, like tha t of Aristot le, is a philosophy of substances. Onlysubstances exist. Th e term en s in its proper meaning ca n only be predi-cated of substances or subsisten! wholes of being. Esse, as St . Thomasrepeatedly states, cannot be predicated of accidents in its proper sense,but only analogically. The esse of the accidents is an inesse. Accidentsonly exist in and by virtue of substance. It fol lows that the possibiliaesse et non esse ar e substances which ar e such that they ca n also no tex is t . That there ar e subs tances of this fi rs t type becomes right awayclear from the fact that there are subs tances which begin to exist bygenerat ion and cease to exist by corr rup t ion . B u t that there ar e sub-stances of the second type has to be shown by a r g u m e n t .The meaning of these notions must however be made even moreprecise. Th e substances of the first type ar e substances which by theirvery nature, by v i r t u e o their ontological s tatus are such that they ca nas wel l exist as not exist . Why? Because their status of being is deter-i n incd by two essen t i a l f ac tor s : th e part icular essential form which givesi l i e i r esse substantide and the materia prima, b y which they are notuccessari ly determined by tha t de termnate fo rm by which they ar e actual lyde t e rmined. The same mat ter which is fi rs t determined by this part icularforma to consti tute together with i t this part icular substance, can alsobe d e t e r m i n e d by another par t i cu la r - fo rm, to consti tute together wih itsnother substance. T he change by which in the same matter tw o part i -

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cula r formas follow the one after th e other , is a passing away whichnecessarily carries with it the coming-into-being of another substance. Fo rth e materia prima, because of i ts very nature, can never exist on i tselfwithout being determined by a forma, together with which it constitutes,by way of composi t ion, on e material substance. Once more, only sub-stances exist. The materia prima cannot have any esse by i tself becausei t does not have any determination by i tself.The reason why certain substances ma y exist as well as not exist,is the materia prima, which, by i ts very nature, indifferently undergoesdetermination by whichever defini te form which gives the compositumits esse substantiale: omnis forma dat su o subjecto esse secundum i l lam-f or mam. Th e forma substantial is or the essential form (for instance, humanness ) gives the subject or the individual being its esse substan-tiale, that is, to be this man; a forma accidental is ( for in s tance , white )gives the subject an esse accidntale, that is, to be this white thing. Thet ransi t ion from on e subs tance to another is therefore called a mutatiosubstantialis. Now, when a substance is by i ts nature such that i t canchange into another substance, this will happen if things ar e allowed tofollow their natural course. Henee: quod possibile est non esse aliquandonon est.The addit ion when things are allowed to follow their naturalcourse is important . For God could in a miraculous way, for everkeep in existence a possibile esse et non esse. But this as sumpt ioncannot be made in our argument, because our argument has precisely thepurpose of demonstrat ing the existence of God. Fo r that reason, w ecannot consider the possibili ty of a miraculously keeping in existence inour p resen t a rgument .Th e same holds true for the necessarium. Generally speaking thenecessarium is a subs tance which by i ts nature is such that when itexists , it cannot cease to exist , because it does n ot carry within i tselfsuch a principie by which i t is related indifferently to any possibleforma substantialis: an d this either, as in the case of an ngel, becauseit is pur form and has no material component, or, as is the case withthe celestial bodies, at least according to the peculiar Aristotelico-Thomist iccosmology, because their matter is of a d i f fe ren t kind, which does no tallow i t to be determined by another forma than this one whichdetermines it actually. It is only in potentia ai unum.Now, on account of the same principie which we applied to thepossibilia, we should say of the necessaria tha t a substance which initself does no t have a principie of being by which it would be able tocease to exist, will as a mat ter of fact exist for ever , if things ar e allowedto follow their natural course. That they could miraculously cease to


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T E R T I A VI A

is again an as sum pt ion, fo r which there is no place in our a r g u m e n t ,it a lready presupposes the conclusin.We said of the necessarium that it is a substance of which non-is impossible, at least if it exists. For is is not impossible thatday it began to exist. But once it exists according to its own waybeing, it has the power to cont inu to exis t for ever. And becausebeing has as such a desiderium naturale essendi (a na tura l des i reexis t ) , it w il l not out of itself cease to exis t , when it has by it selfe power to cont inu to exist . St . Thomas says it in t h is way : illudvir t u t em ut si t s e m p e r , ex quo habet illam v i r t u t e m , no n

fui t . Unde haec ratio, quae poni t ur ab Aristotele, non concludit sim-quod incorruptibilia no n inceperunt e s se ; se d quod no n inceperuntper modum natu ra lem, quo generabilia et corruptibilia incipiunt ( 1 ). Th e obciens here ha d conc luded f rom Aris to t l e : every th ing

inco r rupt ib le be ing has a beginning in its exis tence . S t. Thomasf rom this argument only fol lows that the incorrupt ibledo not begin to exist in the s a m e way as the generabilia an dThey can, t he re fo re , begin to exist in a d i f fe ren tviz. by creation. But for the latter possibility there is, again, noin the a rgumenta t ion of the tertia va, because it m u s t preciselythe existence of a Creator . For this reason St . Thomas here onlyfrorn th e fact t h a t a substance is inco r rupt ib le i t canbe shown tha t it had no beginning or t ha t itbeginning. This conclusin is of grea t impor t ance in the ent ired e aeternitate mundi.

It has now become clear that in the order of concepts a clistinctionbe made betwee n a condit ional and an unco ndit ional necessity .condition is: if it exists. Conditional necessity properly belongsthose subs t ances wh ich by themse lves canno t cease to exist once

( 1 ) Summa theologica, 1 , 46, 1 ad 2. The object ion , which is here answeredbeen borrowed frir i Ai b t o t l e ' s De celo et mundo. In hi s commentary S t . Tho-s fol lov/ ing in the foots teps of the philosopher declares that everything whichalways, exists arways necessarily. This does howeyer no t mean that wh a t e v e rnecessarily, exists alwoys. He explains the first statement with the follow-g v / o r d s : Illud quod s em p c r e s t , sci l, pe r in f in i tum tempus, haber potentiatnsi t in inf ini to tempere: potent ia autem existendi non es t ad ut rumque respectu

quis potest esse; omnia enim appetunt esse, et u n u m q u o d q u e t a n -es t quantum potest esse . Et ho c praecipue patet i n hi s quae sunt a n a t u r a , qu iaes t determnala ad u n u m . Et sic quidquid semper est , no n contingentrsed ex necess i tate . . . . Et s i c patet , quod ornne quod est se rnpi t e rnurn ,t ingen i tum e t i ncor rupt ib i le . (Opera omnia, edi t . leonina, 1886, p. 106).

J. H. W A L G R A V E

they exist . Uncondit ional necessity would then belong to a substance,with regard to which th e condit ion if it exis ts makes no sense, becauseits own being or essence includes exis tence, so that it has in its ownessence the grou nd of it s necessity . To de m nstrate the exis tence of sucha being is the proper purpose of the tertia va.The argument

There are substances which cease to exist by na tura l co r rupt ionan d begin t o exis t by na tura l generat ion. Henee they are possibilia esseet non esse. From their very na ture it fol lows that they do not have th epower to exist for ever . This is the fact.The principie then runs: it is impossible that substances of such anature, when left to the natural course of things, would exist for ever.Because by themselves they do not have the power to exis t for ever,they cannot exercise this power. Left to themselves they will in thenatu ral course of things once cease to exis t . This is the meaning of thei m p o r t a n t proposition a l ready quo ted: quod possible est non essealiquando non est .But now comes the difficulty: Si igitur omnia sunt possibil ia esseet non esse, aliquando nihil fui t in rebus . Is that true, then all fur the rconclusions fol low. H as there once been absolutely nothing, then alsonow there is nothing. For somethitig can only begin to exist by somethingthat exis ts . E x nibilo nihil. From no th ing no th ing comes fo r th . Now,it is ir refutably wrong that now nothing exis ts . Henee it is impossiblethat at some m o m e n t there was not anyth ing a t a l l . Tha t a rgum ent i snothing else but an appl ication of the pr inc ipie of causality at itsdeepest level. In the f i r s t proo f of God's existence the principie wasformulated in this way: omne quod. movetur ab alio movetur. This isthe positive formulat ion of what, negatively formulated, runs like this:nihi l potest mover seipsum. We can formlate this more elaborately asfol lows: every substance, which is sub jec t to change , unclergoes thischange by the causal inf luence of another substance. In the third proof

" th e pr inc ipie runs : quod al iquando no n est, no n incipit esse nisi pe r aliquidquod es t or a substance can only begin to exis t by the eff ic ient causalin f luen ce of another substance which already exis t s be fo re . A nd then,indeed , if once there was nothing, nothing could begin to exist.Th e difficulty l ies therefore in the asser t ion t ha t , if all substancesor beings which make up the totality of being, were of such a n a t u r ethat they come forth the one from th e other in na tura l succession bycorrup t ion and ge nerat ion , there once was nothing. This imp lies ofcourse the logical assumption that the conveyor belt of possibil ia back-wards o r t oward the pas t canno t inf initely go on. For, if this would


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70 TERTIA VI A

be possible, the conclusin aliquando nihil fuit in rebus would belogically wrong. But is a never ending succession of particular forms inan eternal mat t e r logically really inconceivable? Does not S t. Thomashimself say: n o n est impossibile quod homo generetur ab hominein infinitum ? (2).To get a clearer view of this problem we m u s t bear in mind thatthere is question here of a temporal succession of substances in the samematter. These substances can as a matter o fact be counted. We musthowever make a distinction between count ing toward th e past an dcount ing toward th e f u t u r e . Tf we count toward th e f u t u r e , we cansa y that we can infinitely continu, or, rather, go on without end:strictly speaking no t in infinitum (the infinitum is never reached), bu tin indefinitum. With this I intend to say that we can n o t hope to reachat some moment a point, where the infinite is reached. This wouldimply an int r insic contradict ion. B y going on counting one can neverreach th e infinite, fo r what can be counted is by its very nature fini tean d at number 5 billion we are not yet any closer to the infinite trian atn u m b e r five , But we can say that the succession of numerables will goon without end. Nothing in the nature of the progressive succession tellsthat it must at one moment come to a stand.

If, on the other hand, f rom what now is we count backward to thepas t , the entire situation changes. For each unit in the past series didhave a real existence When I say that the succession is already fromal l eternity going on. I ipso fact o state that a real infinite series ha sbeen real ised at this moment. B ut this is obviously nonsensical . For ifthe infinite has now been reached, the next unit in the series will be:infinite + 1. And this involves a contradiction. For, because of its veryn a t u r e one cannot add fur ther units to what is infinite. N o substance ca ntherefore be the terminal point of an infinite series. Consequently thep a s t series is fini te and did have somewhere a beginning, even if theser ies were a billion t imes a billion t imes a billion. If everything thatexists were of such a nature that it would only be once a link in anumerable series, then there would indeed be a beginning and beforet l i i s b eg in n in g there w as nothing. A n infini te ly progess ive series ispossible, but a realised infinite series is impossible.

This is w hy St . Thomas says: O m n e m multitudinem oportet essen aliqa specie mul t i tud in i s . Species au tem mul t i tud in i s sunt speciesm.i mero rum. Nulla autem species multitulinis est infinita; quia quilibetnumerus es t mul t i tudo mensral a per unum. Unde impossibile es t essem u l t i t u d i n e m i n f i n i t am a c t u ; sive per se, sive per accidens. Se d esse( ;: ) Stwiii i ,i th'd., , 46, 2 ad 7.

J. H. W A L G R A Y E

mul t i tud inem infinitam in po tent ia possibile es t (3 ). Whether there squestion of a number of simultaneously existing units or of a numberin succession, does not make the least difference.O ne can n o t escape f rom th e absutdity of the assertion that every-thing which is consists of possibilia, unless when one adds that amongthings there also ar e necessaria an d then the sequence of the argumentgoes on with stern logic.

Now, as we have already seen, necessary substances are either con-ditionally necessary, that is, if they exist, or unconditionally necessary,that is without more ado. This di l emma is given with the order ofconcepts and that by virtute of the principie of non-contradiction. Con-ditionally necessary substances cannot na.tura.uter cease to exist, if theyexist. This condit ion lying in their very existence implies of course thateven if they would in fact exist eternally and without a beginning, theywould nevertheless be contingent. For a contingent substance means thatits existence, regardless of whether it be sempiternum or limitecl induration, does not have its ground or reason in the essence, in the quodquid est of that substance. For then it would have the ground of itsexistence in its own essence, and exist eternally or without beginningin such a way that the condition if it exists would no longer havean y meaning whatsoever.T he argument, however, is more intricate than it seems to be at af irst glance. St. Thomas has obviously shown that not everything whichexists , can belong to the order of the possibilia. Therefore, there mustbe among th e existing substances necessary subs tances , or at least on enecessary substance.

Now St. Thomas admits not only the possibility but also the factualexis tence of necessary beings which do not have the ground o theirnecessity in themselves. It is with regard to these beings that he holdsthat philosophy cannot ascertain whether they exist eternally or not.Either did they begin to exist, or do they exist eternally. Which of thesetwo propositions is correct, cannot be made out by the philosopher onthe basis of philosophical arguments.

There are , therefore, philosophically speaking two possibilities withregard to the necessary substances, which do not have the ground oftheir necessity within themselves or in their own being.

There is, in the first place, the possibility that their existence hada beginning. But then the problem of the possibilia r emains withoutsolution. For, with regard to these necessaria we must say what we alsosay concerning the possibilia: If everything that is , would be of such

(3) Op. di., I, 7, 4 c.


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a nature, at some moment there was nothing in the order of things. Andso the g a m e starts al l over again without ou r being any closer to thesolut ion.We mu st , therefore, t ry the second solut ion: there are perhapsnecessary substances which exis t eternal ly .As we have seen, th e philosopher cannot exclude this possibil ity .Has the problem been solved with the assumption that there ar e amongthings e t e rna l neces sa ry subs t ances? As fo r th e probelm of a beginning,the answer is aff i rmat ive , because if there are eternal necessary sub-stances , it can no longer be concluded : aliquando nihil fu i t in rebus .When -w e consider the not ion of an eternal necessary substance:a new m etaphys ica l probleem looms up and even a c ruc ia l one . Does

that eternal necessary subs tance have the ground of it s eternal necessaryexistence in i t se l f? Is it itself the caus of it s eternal and necessaryesse? We are always dealing with the same dilemma of causal i ty : eitherby itself or by ano ther . In the prima va this w as stated in the t e rms :nothing ca n change itself . Henee everything that undergoes change , ischanged by another. Here this is expressed at a deeper level: Thatwhich does not have the esse by itself, cannot give it to itself. Therefore,it must receive it s esse from another substance.Once we have reached this point , the logical sequel is : if thesecond eternal necessary substance, which is supposed to give esse toth e f i r s t , is itself such that it does no t h a v e it s esse by its own essence,we must ask with regard to the cause of that esse the same quest ionas the one we asked concerning the f irst eternal and necessary substance.And in this way v/e are again on the impossible road of the procederin infinitum, This proceder in infinitum is nonsensical for the samef u n d a m e n t a l reason why it was found to be so in the prima va. For it isa series per se. Obviously it cannot be a series per accidens, for thecausal relat ionship between eternal subs tance s does not take place in

t i m e . Henee the necessary substance, which does not have the groundof it s necessary esse in it self , eternally receives it s necessary exis tencef rom ano ther an d tha t means , in the last analysis , from an eternalsubstance which does no t need an y more to rece ive it s eternal exis tencefrom another, because it has the esse by vr tue of it s essence, or , in otherwords , it is i tself the esse subsistens: the substance, the essence of whichis th e esse it self . And this is God.It is obvious t ha t th e t h i rd way , as the second and the four th ,goes deeper than th e first . This had as its point of departure thatcertain substances are sub jec t to change. Now, s ince in every thingwhich undergoes cha nge, .this chang e mu st be caused by something else,we must , if we logical ly pursue the aurgment , conclude that there is a

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f irst mover, which in the act , by which it act ively changes others , isno t it self subject to change: Aris tot le ' s U n m o v e d Mover . Th e conclusinis therefore not formal ly the aff i rmat ion of a creator. But the tertiais no t concerned with th e changes subs t ances undergo , bu t with theexistence itself of substances.. Th e possibilia, of which .w e know fromexperience the chain of coming-into-being, forc us to affirm the existenceof necessaa or necessary substances. Regardless of whether these hada beginning or not this cannot be decided philosophically , at anyrate they have the esse, be it with or without beginning , eitherpe r participationem, by par t aking in the esse that is pe r essentiam, orpe r essentiam, by their own essence, because their essence is their being.This las t metaphysical alternative i s a t t he s ame t ime the fundamenta lintuit ion on the basis of which St . Thomas is going to clevelop bis doc-trine of creat ion: Si enim aliquid i nven i tu r in al iquo per part icipa-t ionem, necesse est quod c a u s e t u r in ipso ab eo cui essent ial iter conve-ni t or Ex hoc quod al iquid est ens per par t ic ipa t ionem, sequi t urquod sit causatum ab al io (").As you all know, this is th e a r g u m e n t , th e only a rgument and i tis a philosophical one with which St. Thomas in the very firs t art icleof his t reat ise on creat ion demontrates that al l beings necessarily receivetheir being from God's creat ive act ivity: Respondeo dicendum quodnecesse es t dicere omne ens quocumque modo est , a Deo esse . In wri t -in g this he only renders explicit , in a sequel of thought which goes f romGod to the exist ing things, what he already ha d reached in a sequelof thought which in the quinqu viae w e n t f rom th e t h ings to God. Inthe secunda, tertia and quarta va God ad Creator already is the formalterminal point of the argum enta t ion.For in the secunda vi a it is shown that in the order of causes theremust be a a f irst cause wh ich both in the final effect an d in al l interme-date causes causes being in every aspect of being, because being isthe exclusive proper effect of that fi rs t cause. The lat ter causes thereforeeverything sub ralione entis. N ow this is peculiar to creat ive causality .

In the tertia via it is shown that there is an absolutely necessarybeing, a being for which it is impossible not to be because it has thecause of its necessary existence within it self , that is , in it s own essence,and that for this reason grants being to all subs'.anees, even to suchsubstances which might exis t eternally and necessarily , if these do notcarry within themselves the ground of their necessity . This means , in i t smos t acut e formulat ion , t ha t every being, even an eternal necessarybeing, mus t come to existence by creat ion, if i: is not being per essentiam.

(4 ) Op.cit., I, 44, 1 c and ad 1.


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74 TERTIA VIA

In the quarta va it will be shown that in substances in wich theperfection of being s .only realised in a limited way, that is more or less,henee partially, that perfect ion which lies in them, is caused by amximum, that is, a substance in which the perfection of being isrealised without limit, in its pur fullness, henee in such a way that itcannot be placed in the series of more or less, bu t t ranscends withoutlimit, that is infinitely, the en tire series.

What I want to say with this is that the formal final conclusions,to which th e second, thrd and four th ways take us with logical necessity,can directly be stated in the terms of the principal characteristic of therelation of created being to its creator: From the fact that somethingpossesses being in the manner of particpation follows that this beingin it is caused by a being that by itself is p u r and henee infinite being .

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