Sonderdrucke aus der Albert-Ludwigs-Universität Freiburg KLAUS JACOBI Abelard and Frege: The semantics of words and propositions Originalbeitrag erschienen in: Vito M. Abrusci (Hrsg.): Atti del Convegno Internazionale di Storia della Logica : San Gimignano, 4 - 8 dic. 1982. Bologna: Ed. CLUEB, 1983, S. [81] - 96 A 7TI dd Convr~noInlrrnazionulr di Boria drllo Lo~ic-U. Saii Giiriigiinno. 4-8 diicrnbrc 1982. (-'IIJFIt. tIoIog11a (llaly) C) 1983. ABELARD AND FREGE: THE SEMANTlCS OF WORDS AND PROPOSITIONS Klaus Jacobi Universiiic lluisburg, Ciesaniihochschulc. FB I - Fach Philosophic. Lotharstr. 65. 4100 Duibburg Petcr iibrlard was born in the year 1079 and djcd in 1142. Gottlob Frcge lived from 1848 to 1925. Frcgc's Begriffsschrift was published in 1879, eight hundred years after Abelard's birth. Historians of uhilosophy say that cach man marks the beginning of an epoch in the history of logic, and beyond that, that each left a deep imprint on thc coursc of further developments. It is wcll-known that Preqe felt himself isolated and deprived of due recognjtion. Fcw of his colleaques, whether from thc-mathe- matics or the philosophy dcpartmcnt, bothered to study his works. Surcly none of his contemporaries adjudqed Frege's works to be epoch-makina. Nor did F'regc havc students who continucd his in- vestigations. His impact began with Russeii, Wittgenstein, and Carnap. Although the threc diffcr widely in the style of thcir thinking and in the questions they pose, all claim Freqe as their true intellectual fathcr. Abelard, on the other hand, found cnthusiastic listeners wherever he lcctured. He was a famous man, such that the mention of his namc cvokcd either sreat admiration or bitter enmity. Nonetheless, thc substance of his success as a teacher is not casy to grasp. Abelard was not dcstined to found a ncw nhilo- sophical tradition, as Peter Lombard and latcr Thomas Aquinas and John Duns Scotus were. Abelard was never an "authority" in thc scnsc in which thc scholdstics used the word. His influence is less to be attributed to a sct of theses which he developed than to his distinctive manner of approaching questions. The historical transmission of his thcological and loqical works was weak, but his philosophically probinq, discussinq, and analyzinq attitude toward knowledgc camc to be reaarded as exemplary. Frege was not familiar with Abelard or any of the other scholastics. Thcre is no hjstorical connection between the two philosophers, be it direct or indirect. When I speak on Rbelard and Fregc hcre, the theme is selected with different intentions from thosc for a papcr on say Freqe and Leibniz. I intend to conduct a comparison in systematic perspective. This comparison cannot bc bascd on thc dcmonstration of an influence of Abelard on Preqe undiscovered until now or upon somc aqreeing or dis- senting reference to Abelard in Freqe's works. Thus I vould likc to provide you witha brief explanation of what motivated me to the comparison. First, I wish to makc clcar that in selectinu this theme I do not intend to Open a debate nn Progress or reqrcssion in phi.10- sophy or the field of logic. I am not goinq to have the two philosophcrs compete with each other. I am not going t-o measure the one against the other. Thus no attempt will be madc here to demonstrate that Abelard "anticipated" later insights of Frege or that Freqe "rediscovered" carlier insiqhts which Abelard had reached. In my lectures and writings on scholastic loqic, I am con- fronted with thc problem of translatinq the medieval technical terms into a modern vocabulary. One has no choicc herc but to cmploy words whi.ch have become technical terms in modcrn loqic theory thanks to Freqe and his successors. Now we are often warned of the dangcrs inherent in a translation of scholastic d.iscussions into modern synibolic lanquagc. But whercas onc can forego such translations or devclop a more appropriate syrnbolisni in the field of loqical Syntax, in scmantics and philosophy of logic onc cannot avoid the dangcr of misinterpretation by simply renouncing all translation. One docsn'l: nct very far without such terms as 'sense', 'refcrcncc', 'designation', and 'dcnomination'. In ordinary languagc, these terms have hroad semantic fields. Thcy are used in various senses which oftcn ovcrlap. In scholarly usage the mcaninqs of such terms arc defined more precisely, at the very minimum by coordinatin~them wiLh or scttinq thcm in opposition to other terms within thc theory nt hnnd. When one makcs use of them to translate scholastic terms, it is necessary to state plainly which scnse is considered appropriatc ror thc new context. A rcturn to the everyday usagc can hardly be satis- factory, for the philnsophical or scientific theorics within which these words havc become technical tcrnis must also be taken into consideration. I am myself better versed in thc scholastic scientia sermo- --cinalis khan in modern theorics of loqic. Occasionally, in reading Fregc or one of his succcssors, I try out translations into the tcrminoloqy of thc scholastic controversics in ordcr to sharpen my conception of thc problem under discussinn. In- evitably, I ask myselF if any similaritics between the modern trains OE thought and ccrtain positions in the scholastic con- troversies can be found, This is of Course just as much a matter of clarifying thc differences as of holdinq on to TO- inciding elemcnts. Abclard stands at the outset of the scholastic development in loqic, Frege at the outset of modern developments. Neither finds a finished terminology for his philosoylhical investiqa- tions laid at his disposal. He must develop such a terminology himsclf. In questions of semantics, Abelard could find more Support in the preparatory work of his predccessors than Freqe. Abelard worked on questions which had been dealt with hy Boethius, Priscian, grammarians of the time, and Abelard's own logic teachers. Yet his lanquage often impresses us as being awkward and forccd in comparison with the crystalline clarity and elcqant brevity of tiiqh sctiolnst i.c aiithors. On thc othcr hand, Ahclard is free of ttie Set scheniata of qucstioninq and thinking wiiich bccamc charactc:ristic of later sctiolastics. He discussed lincjuistic [ihenomena such as impersonal. construct i.ons whi ch arc lat.cr ncgl.cctcd bc:causc they arc sim~lynot accessible to ttie analytic iristrunients of the thcory of the sup~iosj.tio.Ire furthcrmorc considcred alternative approaches to sucti problems as the theory of predication, whereas later other authors dis- cusscd a conspiciously narrowcr spcctrum oF lihcorics. - The samc can gcncrally be said of Frcqc in comparison with say Carnap, to takc onc cxamplc. Frcgc Corcihly wrcsLcd his tcrmino- loqical distinctions, such as that between 'Sinn' and 'Weutung' , froin ttie languacyc, whcreas Carriap simply laid down such distinc- tions by definition. Freqe strained to dcvelo? adequate formu- 1.ations 01 new questions and to discover new intergretational t.cchniqucs. IIis successors rnerely took ttiern over. - Thus it sccms Lhat a comparison 01 Abelard and Freqe recommends itself as a starting point whcn onc wishes to undcrt-akc a comparison 01 scholastic and rriodern loc~ic. Howevcr, a comparison will be mcaningful only if thcrc is a manifest Consensus on relevant points. This also tiolds wtien Lhc objcct of the comy?arison is to point out the differences in the rcspccLivc positions. Or coursc, d i.sti nctions arc of valiic only when it is possible to mark out preciselv to wtiat extent the basis upon which the disLincLions havc bccn drawn is a common one. Thus the question presents itself whcther this fundamental prcrcquisitc For a comyiarison is fulfilled in our case. Well, in the Course of rny studies of Abelard with an cyc to parallels to Preqc and of Frcgc wiLh an eye to Abclard, I have swayed back and rort-h on how to answer ttiis r:uestion. Sornetimes I find a surprising dcgrce OE similarity in the way each approaches semantic questions, despite their quitc diffcrcnL sLartinq points - for Abclard thc scicniia scrmoncinal is as a Loqical analysis of the language of argumcnLaiion and scholarly in- vcstj.ga(iion, Tor Freqe the demonstration ttiat ttie axiorns of arithmetic acc of a purely lociical nature. At ottier times, I sccm to have deceived niyself: the aqreemcnt secms to be no more ttiari verbal - cach man uscs cxnressions which sound prac- tically alike to discuss cornpletcly diFFcrcnti mattcrs. To work my wav out of this con"usion, I have carefully noted what it is T pay attention to in eacti case. 1 would li.kc t-o take you alonq for a part of my scarch. In the cxccl,lcnt prcscnLati.on of Ircqc's work givcn by Willia~nKneale, onc finds thc following: "In thc ordinary use 01 languaqe for maklncj statements, asking yuestions, qiving orders, &C., ii is to bc assumed that every dist-inquishable complctc sign has both sense and reference. The reference is an object of some kind, but not nccessarily a perceptible object. ... Thc sense, on the ottier hand, is sorncthing by which the object may bc singlcd out for attention. It is not an idca, if by that we mean an imaqe or sorncthing private to an individual thinkcr. For all comniunication dcpends on thc exnression of sense by one man to another, and in spccial circumstances siys may have a public sense cvcn though they lack all reference." 84 KIA IJS JA CORI (The Development of Loqic, p. 496; cf. p. 578). The Passage could be taken word for word to characterize Abe- lard's semantics. Comparc: "Nomina ... et verba duplicem siqni- ficationem habent, unam cpidrm dc rcbus, altcram dc intcllccti- ,~us.Res enim significant constituendo intellectus ad eas per- tinentes, hoc est naturam aliquam earum vel proprietatem at- tendentes." (Super Peri crm., 307, 26-30; cf.