Introduction to Ontology From Carnap and Quine to Hilary Putnam

1. Introduction to OntologyFromCarnap and Quine to HilaryPutnam @emanuelrutten VU University Material in thiscourse-presentation is primarilyobtainedfrom A. L. Thomasson’s essay Carnap and the Prospectsfor Easy Ontology and from essays from H. Price, J. Schaffer and S. Soames in Metametaphysics: New Essays on the Foundations of Ontology (MM)

2. The anti-metaphysicalmovement • By the late 1940s logicalpositivismorlogicalempiricismrepresented the furtherestadvance of the anti-metaphysicalmovement • Logical positivists launched the verification criterion. Empirical verifiable statements are cognitively meaningful, empirical unverifiable statements are cognitively meaningless • The chief architect of logicalpositivism was Rudolf Carnap. He had a puritanicaldevotion to empiricism, and offered a radicaldeflationary view of metaphysics • According to this view all questions of traditional ‘a priori’ metaphysics are pseudo-questions. Theylackcognitive content (and can’tthereforebeobjects of thoughtorassertion) • So, by the late 1940s metaphysics was supposed to beonits last legs. Actually, it was supposed to bedead. Onebelieved to have finishedwhat Kant started [Huw Price in MM]

3. The revival of metaphysics • Yet, Carnap’sposition was neverconsolidated. In fact, the ground was lost • For one of the features of contemporaryanalyticphilosophythatCarnapwould have found most surprising is the apparenthealth of metaphysicsorontology “Howcome,” the reader may wonder, “it is precisely in analyticphilosophy - a kind of philosophythat, formanyyears, was hostile to the very word ‘ontology’ – thatontologyflourishes?” If we askwhenontologybecame a respectable subject forananalyticphilosopher to pursue, the mysterydisappears. Itbecamerespectable in 1948, whenQuinepublished a famous paper ‘OnWhatThere Is’. It was Quinewho single handedly made ontology a respectable subject again.” (Putnam in 2004) • According to Putnamit was Quine – perhapsQuinealone – whorescuedmetaphysics. His ‘OnWhatThere is’ gave Ontology a life-savingtransfusion [Huw Price in MM]

4. Quine’smethodfordoingseriousOntology • On the now dominant Quinean view, metaphysics is aboutwhatthere is. Do propertiesexist? Do numbersexist? Do meaningsexist? Do tables and chairsexist? Do temporal partsexist? Mereologicalsums? Propositions? Etc. • Quine’sfour-stageindispensabilitymethodfordoingseriousontology (1)Identify the best scientifictheory (physicsforQuine) (2)Identify the canonicallogic (first order predicatelogicforQuine) (3) Translate the best theoryinto the canonicallogic (someparaphrasingallowed) (4) Determine the ontologicalcommitmentsrequired to renderthistranslationtrue Example: The indispensability of mathematics to empirical science gives us good reason to believe in the existence of mathematical entities. Reference to mathematical entities such as numbers is indispensable to our best scientific theories, and so we ought to be committed to the existence of these entities (Quine-Putnam indispensability argument) [(J. Schaffer in) MM]

5. Carnap is a Platonistaccording to Quine • OnQuine’s view of doingseriousOntologyCarnap is in fact a Platonist (!), sinceCarnap is in hislogical-empiricaltheoriescommitted to the existence of numbers, properties and other abstract objects • Quinehimselfalsorecognizes the existence of numbers as “a regrettableform of Platonism” – they are apparentlyunavoidable in our best physicaltheory. • The samecannotbesaid, Quinethinks, forproperties and other abstracta • ButhowcouldQuine have calledCarnap a Platonist? Platonism is among the • traditional metaphysical views Carnap had consistentlydismissed as cognitivemeaninglessnonsense. HisLogicalEmpiricism was supposed to leave traditional • metaphysicsbehind • Ifsomeone as sympathetic to positivism as QuinecouldreadPlatonismintohis project, Carnapwould have to state hisposition more cleary. This was the task of his 1950 article ‘Empiricism, Semantics, and Ontology’ [S. Soames in MM]

6. Carnap’sdeflationary view of metaphysics: ontology is shallowinstead of substantive • There are two kinds of questionsconcerning the existence of entities: internalquestions and externalquestions • Internalquestions are questions of the existence of certainentitieswithin a givenlinguisticframework of terms and rulesforapplying these terms • Empiricalinternalquestions: Is there a white piece of paper onmy desk? (askedwithin the languageforordinarythings - “the thinglanguage”) • Analyticalinternalquestions: Is there a prime numbergreaterthan 100? (askedwithin the languagefornaturalnumbers - “the system of naturalnumbers”) • Answers to specificinternalexistencequestions are foundstraightforwardlyby the analytical (e.g., mathematics) orempirical (e.g., looking) rules of the • framework, dependingonwhether the framework is a logicalorfactualone • Answers to generalinternalexistencequestions are foundeasily as well, by direct entailmentfrom the specificexistenceassertions. For example: ‘Five • is a number’ entails ‘Numbersexist’ or ‘Red is a color’ entails ‘Colorsexist’ [A. Thomasson]

7. Carnap’sdeflationary view of metaphysics: ontology is shallowinstead of substantive (cont.) • Externalexistencequestions are questions of the existence of certainentitiessimpliciter, that is to say, apart fromanygivenlinguisticframework • The terms in these questions are thusdivorcedfromframeworkapplicationrules (semanticrules) thatgoverntheirusage and constitutetheirmeaning • As a resultexternalquestions are cognitivelymeaninglesspseudo-questionsthatcan’tbeanswered • Traditional metaphysicians offer lengthyphilosophicalargumentsfortheir claims, such as thatnumbersexist. Sotheycannot have in mind the rathertriviallyanswerableinternalexistencequestions • The sense in which traditional metaphysicalquestions are raised must therefore • beexternal. Butthen all questionsfrom traditional metaphysics are ill-formedunintelligiblepseudoquestions • Hence, neither the Nominalist’s nor the Platonist’sanswer to the question ‘Do numbersexist?’, taken as anexternalquestion, shouldbeembraced. Ontology as • the practice of answeringexternalexistencequestions is simplyfutile [A. Thomasson]

8. Carnap’sdeflationary view of metaphysics: ontology is shallowinstead of substantive (cont.) • Externalexistencequestionsas theoreticalorfactualquestionsare thusmeaningless. Oneshouldnotaskwhatreallyexists. For that is senseless • And that is whyCarnapcannotbecalled a Platonistafter all • Butexternalexistencequestionscanstillberaisedas practical questions, that is, as pragmaticquestionsaboutwhetherornot to usesomelinguisticframeworkfor a specific practical purpose • Pragmaticexternalquestions do have theoreticalorfactualaspects. For it is a factual matter whetherforexamplea framework of things(enablingus to speak of e.g. • atoms) is - or is not - more effectivefordoingempirical research thana • minimalisticphenomenologicalframework (allowing talk of ‘sense data’ only) • Ontologybecomesthusshallow in the sensethatit is limited to ‘conceptual engineering’, that is, making practical decisionsabout the advisability of adopting and usingcertainlinguisticframeworksforspecific goals [MM &Thomasson]

9. Carnap’sinternal-externaldistinction in terms of the use-mentiondistinction • Legitimateuses of the termssuch as ‘number’ and ‘material object’ must beinternal, forit is conformity to the rules of the framework in questionthatconstitutesuse. But as internalquestions, as Carnapnotes, these questionscouldnot have the significancethat traditional metaphysicstakethem to have. Metaphysicstries to locatethemsomewhereelse, buttherebycommits a use-mentionfallacy. The onlylegitimateexternalquestionssimplymention the terms in question (Huw Price) • Internalquestions are askedwithinorusing the framework. Theymakeuse of the relevant terms (propertyterms, numberterms, material object terms) according to the frameworkrules of application. Withthoserules we caneasilyevaluate the truth of existentialsentencescontainingthoseterms. The usage of terms is governedbyrules, and therefore we must beusing a framework to askexistentialquestions • Without thoserules the termscanthereforenotbeused. And that’swhyfactualexternalexistencequestions are meaningless • Without thoserules these termscanonlybementionedas part of the practical question of whether we shouldadopt the terms – numbers, properties, etc. - in ourframework [A. Thomasson]

10. Does Carnap’sdeflationismentailanti-realism? • According to ananti-realistthere is noobjectivefact of the matter as to whether e.g. materialthings, propertiesornumbersexist. These questions are similar to questionslike ‘What is up?’ or ‘Is Tom Cruise short?’ • Hence, anti-realiststakeitthatwhatthere is dependson the framework we adopt. Existence is (like ‘shortness’ or ‘up’) inherentlyframework-relative • Carnap’sdeflationismdoesn’tforceus to saythatwhatexistsdependson the linguisticframeworkadopted. We cananswerquestionsaboutwhetherthisorthatsort of entityexists – but to ask these questions we must necessarilybeusingsomelanguage, i.e., somelinguisticframeworkthatestablishes the applicationrulesfor the termsused in asking and answering these questions • We thuscannotaskanything apart from a framework. Nevertheless, and this is crucial (!), the answers we express usingsomeframeworkmaystillbetrue. Anti-realism does notnecessarilyfollow. Theremightbeanobjectivefact of the matter as to whatthere is. Somelinguisticframeworksmightbe right [MM]

11. HilaryPutnam’sdeflationism ‘It is characteristic [...] to holdthat ‘Whatobjects does the worldconsists of?’ is a questionthatonlymakessense to askwithin a theory of description. (Putnam 1981) There is no God’s Eye point of view that we can know or usefully imagine; there are only the various points of view of actual persons reflecting various interests and purposes that their descriptions and theories subserve. (Putnam 1981) • Putnamarguesforconceptualrelativity. The question ‘whatexists’ canonlybeanswered in terms of a particular ‘version’, i.e., a particularconceptualschemeorrepresentational system. Questionsaskedoutside all ‘versions’ are rejected • SofarCarnapwould have said the same: the question ‘whatexists’ canonlybeansweredinternal to a linguisticframework – i.e., using a framework. Factualexistencequestionsexternal to a linguisticframework are rejected • Butthere are twowaysin whichPutnam’sdeflationismtakes a different turn (1) The meaning of the core terms ‘exists’ and ‘object’ itselfdiffers in different versions (2)Putnamembracesanti-realism, that is to say, hedenies ‘Realism’ [A. Thomasson]

12. (1) The meaning of ‘exists’ is framework-relative […] the phenomenon of conceptualrelativity […] turnson the factthat the logicalprimitivesthemselves, and in particular the notions of object and existence, have a multitude of different usesratherthanone absolute ‘meaning’ (Putnam, 1987) • (1) is calledquantifiervariance, i.e. the ideathatthere is no single core meaningfor ‘existence’ or ‘there is’ • Carnapdisagrees. For him ‘exists’ is a topic neutral and formal term thatmaybeconjoinedwithmaterialterms of different categories (things, numbers, etc.) whileretaining the same core sense (the same core rules of use) • That is, ‘exists’ is univocal. It has a single core meaning. It’s meaning does notchange (exceptfromsomeanalyticrules, e.g. ‘5 is a number’) when we addnewterms (such as ‘number’) to the frameworklanguage • Illustrations of the univocacy of ‘exists’ • X’sexistiff the number of X’s is largerthan zero’ (Van Inwagen) • X’sexistiffnoteverything is not-X’ (“) • X’sexistiff ‘X’ refers(Horwich) [A. Thomasson]

13. Anexample to clarify (1) Take a Platonist and a Nominalist with respect to the existence of numbers • Putnamwouldsaythat ‘exists’ in the conceptualscheme of the Platonist has a different core meaningfrom ‘exists’ in the conceptualscheme of the Nominalist • Therefore, the Platonistcanwithinhisschemetrulysay ‘Numbersexist’, whereas the Nominalist canin hisschemetrulysay ‘Numbers do notexist’. Both accept the term ‘number’ in theirscheme. Theyalsoagreeonwhatnumbers are. The reasonfortheirdifference is thattheyattribute a different meaning to ‘exist’ (different truth-conditionsforexistence) • Carnapwouldhandlethis case quitedifferently. He holdsthat ‘exists’ is univocal. So the Platonist and Nominalist do notdisagreeon the meaning of ‘exists’ [A. Thomasson]

14. Anexample to clarify (1) [cont.] • Theydifferonwhichmaterialterms(‘sortals’) to adopt in theirschemes. • -- The Platonistadopts the term ‘number’ (hewillsay ‘4 is a number’, which • entails ‘There are numbers’). • -- The Nominalist refuses to adopt the term ‘number’ (heneveruses the term ‘number’ in hissentences. Buthemaystillsaythingslike ‘There are twocars’) • Indeed, IF the Nominalist wouldalso have adopted the term ‘number’ (togetherwithitsanalyticalrules of use) THENhewould have triviallyacceptedthatnumbersexist! • Therefore, the disputebetween the Platonist and Nominalist is merelypragmatic. • Should we (given the purpose at hand) add the term ‘number’ to ourlanguage? [A. Thomasson]

15. (2) Putnam’santi-realism • Putnambelievesthatquantifiervariance is a goodreasonforacceptinganti-realism What is wrong with the notion of objectsexisting ‘independently’ of conceptualschemes is thatthere are nostandardsfor the use of even the logicalnotions apart fromconceptualchoices (Putnam, 1987) […] the ideathatthere is anArchimedean point, or a use of ‘exist’ inherent in the worlditself, fromwhich the question ‘Howmanyobjectsreallyexist?’ makessense, is anillusion. (Putnam, 1987) • Putnamthusconcludesthat we must reject the ideathatthere are objectsthatexistindependently of ourconceptualscheme • In short, hedeniesRealism: • -- The worldconsists in a fixedtotality of mind-independentobjects • -- There is one complete descriptionthatcorresponds to the way the world is • As we have seenCarnap’sdeflationismdoesn’tforceus to accept anti-realismeither [A. Thomasson]

16. So, whydidCarnapiandeflationismlooseground? • Was it indeed Quine in 1948, as Putnamhimselfmaintained in 2004? • According to Amie L. Thomassonit was primairlydue to Putnamhimself, and otherswholinkedCarnap’sdeflationism to quantifiervarianceand anti-realism • For bydoingsoPutnam and others made Carnap’spositionquiteunattractiveformetaphysicians [A. Thomasson]