PLUGGING THE LEAKS IN NEURATH’S SHIP: A DEFENSE OFNATURALISTIC EPISTEMOLOGY

PETER JACCO SAS

SUMMARY. This paper examines the question whether foundational epistemology (“FE”)can be replaced by naturalized epistemology (“NE”). First, it argues that Quine’s defenseof NE is inadequate since it is only based on arguments showing the impossibility ofthe logical empiricist version of FE rather than on arguments for the impossibility ofFE as such. Second, it proposes that a more promising argument for the impossibilityof FE can be found in theMunchhausen-trilemmawhich aims at showing that ultimatefoundations (and, hence, FE) are unattainable. However, Karl-Otto Apel has shown that thistrilemma is unconclusive since it uncritically presupposes the premise that all argumentationis deductive in nature. Apel’s argument implies that FE is possibleif and only if it ispossible to devise a non-deductive foundation (“NDF”). It is argued, however, that thepossibility of NDF cannot be demonstrated. This leads to a situation called theMultatuli-dilemma: we cannot prove thepossibilityof ultimate foundations nor can we prove theimpossibilityof ultimate foundations. This dilemma shows that the discussion about thepossibility of FE is pointless. Thus, it suggests that it is legitimate to replace FE by NE.Barry Stroud and Henri Lauener, however, argue that this replacement is not feasiblesince NE is not capable of refuting scepticism (Stroud) or justifying methodological rules(Lauener). But these objections are shown to be mistaken: First, epistemological scepticismis practically impossible and, hence, does not pose a serious threat to NE. Second, NE iscapable of justifying methodological norms if and only if it makes use of so-calledinternaljustifications. Thus, the final conclusion of this paper is that FE can be replaced by NE.

Key words:foundational epistemology, naturalized epistemology, Munchhausen-trilemma,ultimate foundations, deduction, non-deductive foundations, scepticism, justification ofmethodological norms; W.V.O. Quine, R. Carnap, H. Albert, K.-O. Apel, B. Stroud, H.Lauener

Traditionally – ever since the 17th century – epistemology has been con-ceived of asthe foundational discipline, as thefirst philosophywhichsearches for the unshakable foundations of our knowledge, i.e. of the bodyof our beliefs and assertions. According to this traditional conception ofepistemology, the epistemologist tries to prove the truth of our knowledgeon the basis of absolutely certain principles, that is, on the basis of asser-tions which cannot possibly be doubted, denied, or refuted. Therefore this

Journal for General Philosophy of Science30: 131–153, 1999.c© 1999Kluwer Academic Publishers. Printed in the Netherlands.

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kind of epistemology may aptly be called “foundational epistemology”(henceforth “FE”). The driving force behind FE has always been fear ofradical epistemological scepticism: the proponents of FE feared that whenthe truth of the body of our scientific knowledge cannot be sufficientlyproved, this body would inevitably fall prey to the sceptical distrust of thepossibility of science in general (cf. Kornblith 1985: 3).1

The historical manifestations of FE are well known: In the rationalismof Descartes, Leibniz and Spinoza it was tried to deduce the truth of ourknowledge from the so-called selfevident ideas of intellectual intuition. Inthe empiricism of Locke, Berkeley and Hume it was asked how much ofour knowledge can be proved on the basis of immediatly given and henceindisputable sense data. In the transcendental epistemology of Kant and theneo-Kantians (like Cohen, Natorp, Rickert, etc.) it was not so much triedto actually prove the truth of our knowledge, but rather to prove thepossi-bility of true and objective scientific knowledge on the basis of aprioristicand hence indisputable, transcendental principles. In the idealism of Fichteand Hegel it was tried to prove the truth of our knowledge on the basisof something like the indisputable self-reflection of Reason. In Husserlianphenomenology it was tried to base all knowledge on the indisputablecertainty of pure intuition (i.e.Anschauung). In the logical empiricism ofespecially the early Carnap it was triedfirst to deduce all non-empiricalknowledge (i.e. mathematics and logic) from analytical and hence indis-putable thruths, andsecondto explicate as much empirical knowledge aspossible in terms of a phenomenalistic language, i.e. a language about theimmediately given, namely sense data.

Like no other, Willard Van Orman Quine has broken with this tradition-al conception of epistemology as the first philosophy in which the indis-putable foundations of all knowledge are revealed. According to Quine thetask of epistemology is not so much thefoundational justification, but ratherthe scientific description and explanationof the body of our knowledge.And in this explanation – Quine argues – the epistemologist must inevitablymake use of relevant insights from different sciences like psychology, neu-rology, evolutionary biology and even physics. So according to Quine,epistemology is notmore fundamentalthan the scientific body: epistemol-ogy is just one of the many parts of this body, namely that part which triesto give an empirically adequate description and explanation of the nature,the origin and the possibility of scientific knowledge: “Epistemology, onthis view, is not logically prior somehow to common sense or to the refinedcommon sense which is science; it is part rather of the overall scientificenterprise...” (Quine 1976a: 253) Quine calls this kind of epistemology“naturalized epistemology” (henceforth “NE”). Many philosophers have

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followed Quine in this naturalization of epistemology and therefore NEhas become a flourishing branch of philosophy.2

In this paper I want to investigate whether it is legitimate to replace FEby NE. More precisely, I want to answer the following questions:

(1) It is justified to claim (as Quine does) that FE is impossible anddestined to fail?

(2) Is it justified to conclude (as Quine does) from the eventual failureof FE that epistemology should be naturalized, i.e. that FE should bereplaced by NE?

Question (1) will be answered through an analysis of the foundationalthought of Karl-Otto Apel, since Apel represents a philosophical positiondiametrically opposed to Quine’s position with regard to FE (Section 2–4).Question (2) will be answered through a consideration of some argumentswhich have been brought forth by Barry Stroud and Henri Lauener againstQuine’s NE (Section 5–6): Stroud argues that Quine’s NE cannot escape ageneral sceptical distrust of the possibility of science, while Lauener arguesthat Quine’s NE is not able to perform the most important epistemologicaltask, namely the justification of methodological norms. Ultimately, I willargue that NE is the best option (Section 7). But first it must be made clearwhy Quine claims that FE is impossible and should be replaced ny NE(Section 1).

1. QUINE ON FE AND NE

Quine grounds his defense of NE on the conviction that FE is impossibleand therefore destined to fail, that is, on the conviction that it is impossibleto prove the truth of our scientific body on the basis of ultimate, indisputablefoundations. As Quine (1969b: 127) says: ‘There is no external vantagepoint, no first philosophy. All scientific findings, all scientific conjecturesthat are at present plausible, are therefore in my view as welcome for use inphilosophy as elsewhere.’ However, for Quine “FE” exclusively designatesthe epistemology of the empiricist tradition and within that tradition mainlythe logical empiricism of the early Carnap (cf. Quine 1969a).3 Accordingto this Carnapian logical empiricism, the corpus of scientific knowledgeshould be given indisputable foundations by means of two epistemologicalreductions:

(1) All non-empirical knowledge (i.e. mathematics and logic) should bereduced to analytical truths which are based upon linguistic (i.e. syn-tactic and/or semantic) conventions.

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(2) As much empirical knowledge as possible should be explicated interms of protocol sentences and logico-mathematical constructionson the basis of those protocol sentences; according to the early Car-nap, these protocol sentences should be conceived as sentences aboutimmediately given sense data, whereas Neurath and the later Carnaptook these protocol sentences to be sentences about observed physicalobjects and events.

According to Quine these two logical empiricist reduction-projects (i.e.thetwo dogma’s of empiricismas he (1953) calls them) have failed becauseof the following reasons:ad (1) The attempt to deduce all non-empirical knowledge from some ana-lytical thruths which follow from linguistic conventions, has not succeededfor a couple of reasons. Firstly, because of the partial failure of the foun-dational research program in mathematics of Frege, Peano, Russell andHilbert: this program tried to deduce the whole of arithmetic (and maybegeometry if it could be defined in arithmetical terms) from axiomatisedand formalised logical systems. It became apparent that this reduction ofarithmetic to logic is possible only when use is being made of set theory.And set theory is far from being self-evidently true, as is witnessed by thefact that intuitive set theory leads to Russell’s paradox (cf. Quine 1969a:70). Moreover, it was shown in 1931 by Godel that no first order logicalsystem can give a complete and consistent axiomatisation of arithmetic(cf. ibidem). Secondly, Quine himself developed a fundamental critiqueof the logical empiricist thesis that logic can be deduced from analyticaltruths which are based on linguistic conventions. Already in 1935 – in thearticle Truth by convention– Quine made clear that notall of the theo-rems of logic can be deduced from linguistic conventions, because logicalrules are already needed in the performance of this deduction (cf. Quine1976b: 103). And in the articleTwo dogma’s of empiricismof 1951 Quinedeveloped very strong arguments against the tenability of the concept ofanalyticity itself: this concept is very unclear and cannot be defined withoutcircularities (cf. Quine 1953).ad (2) The attempt to explicate as much empirical knowledge as possiblein terms of protocol sentences has failed mainly because of the followingtwo reasons: First, this attempt inevitably comes to a dead end in Hume’sproblem of induction: no empirical generalisation (such as the formulationof a law of nature) can be verified on the basis of a finite number of observa-tions. Stressing the importance of this problem, Quine (1969a: 72) remarkslaconicly: “The Humean predicament is the human predicament.” Second,as Quine argues in accordance with Duhem, one cannot deduce from anyscientific theory a hypothesis which is or will be unconditionally refuted

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by experimental experience. For when a theory T implies a hypothesis H,and H seems to be at odds with some experimental observation O, so thatT appears to be falsified by O, one can nevertheless always save T fromfalsification in several ways:(a) one can bring about some minor changes in T (such as a change in themeaning of some term), so that it is no longer possible to deduce from Tthe apparently fatal hypothesis H;(b) or one can claim that H is not refuted by O, since O was not a successfulobservation, for example because the experimental set-up wasn’t adequate(“the measuring device was disfunctional”) or because O was the productof hallucination. From this Quine concludes that the holistic conceptionof science is the best: not individual hypotheses, but the body of ourknowledge as a whole is confronted with experience. Therefore no theorycan be refuted by a single observation described by a protocol sentence(cf. Quine 1953: 42).

From this failure of the logical empiricist FE Quine concludes thateverykind of FE is doomed to failure, i.e. that outside the body of our knowledgeone cannot find any certainty, anyArchimedian Pointor FundamentumInconcussumon which one can ground the truth of that body. This meansthat in arguing for the truth of the body of our knowledge, one cannot standoutside that body. ‘There is no such cosmic exile’, as Quine (1960: 275)says. Does this imply that epistemology is completely useless, that thereare no more tasks available for epistemology? No, says Quine, becausealthough the epistemologist cannot give a foundational justification of thebody of our knowledge, he can still try to give a scientific explanation ofthis corpus.4 The task which remains for the epistemologist after the failureof FE is empirical research into the nature, the origin and the possibility ofscientific knowledge, i.e. the scientific search for an empirically adequatedescription and explanation of the fact that human beings develop scientifictheories after being aroused by sensory stimuli. Quine (1969a: 75) puts thisepistemological task thus: ‘The stimulation of his sensory receptors is allthe evidence anybody has had to go on, ultimately, in arriving at his pictureof the world. Why not just see how this construction really proceeds? Whynot settle for psychology?’ And since one cannot find any certainty, anycognitive handhold outside the corpus of our knowledge, the epistemologist– in his attempt to explain the possibility of knowledge – cannot do anythingbut make use of this very same corpus of knowledge, that is, of the mostreliable and plausible insights and resources which are offered by therelevant sciences, such as psychology, neurology, evolutionary biology,etc. ‘No inquiry being possible without some conceptual scheme, we mayas well retain and use the best one we know – right down to the latest

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details of quantummechanics, if we know it and it matters.’ (Quine 1960:4).5 In this manner epistemology becomes NE, i.e. one of the many partsof the scientific corpus, namely that part in which human knowledge itselfis the object of scientific research. Thus epistemology getsnaturalized, asQuine (1969a) says.

To clarify his conception of epistemology as NE Quine often usesNeurath’s well known metaphor: the epistemologist who studies the bodyof our knowledge, resembles a seaman who must rebuild his ship in theopen sea. He cannot rebuild his ship from an external standing point, forexample from a floating dock, and with totally new materials; he is forcedto improve the ship while sailing on it, using the materials which arealready on the ship. Likewise, the epistomologist cannot stand outside thescientific body when he is studying the possibility of scientific knowledge(cf. Quine 1969b: 127).

A striking example of NE is Quine’s explanation of the possibility ofinduction. According to Hume and many other philosophers of science,induction is impossible since an empirical generalisation can never be ver-ified on the basis of a finite number of observations. But – as Quine argues– on the basis of our scientific knowledge of the world we can neverthelessexplain why succesful induction is often possible all the same: Naturalscience has made plausible that the natural world consists of natural kinds,that is, of sets of objects which share an essential, not observable structure.Water, for example, is a natural kind, because it consists of the molecularstructure H2O. But the fact that some objects belong to the same naturalkind also implies that they share some observable properties. For example,it is necessary for organisms of the same genotype to share some phenotypicproperties. Nevertheless, it is very hard to decide on the basis of observ-able properties to which one of all the natural kinds some objects belongs.For all objects show among themselves as many observable differences asobservable similarities (cf. Quine 1969: 117/118). Therefore it is logicallyimpossible to proceed from the observation that each of the objects o1,o2, o3...on has the properties F and G, to the induction that each objectwith property F will also have property G, and vice versa. However, asQuine points out, the ability to make successful inductions has great repro-ductive value and therefore organisms which are able to make successfulinductions will be favoured by natural selection above other organismswhich are not able to make successful inductions: ‘Creatures inveteratelywrong in their inductions have a pathetic but praiseworthy tendency to diebefore reproducing their kind.’ (Quine 1969b: 126) Consequently, the abil-ity to recognise observable properties which are characteristic for objectsof some natural kind has become an innate ability through the process of

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natural selection, since it is possible on the basis of that ability to makesuccessful inductions: if one observes that the objects o1, o2 and o3 eachhave the properties F and G, and F and G are each characteristic for objectsof one and the same natural kind, then one can proceed from this observa-tion to the successful induction that every object with property F will alsohave property G, and vice versa.6

Of course, this Quinean explanation of the possibility of inductionis still only a tentative hypothesis which needs further elaboration andempirical confirmation, but in any case it is a hypothesis which can beempirically tested rather easily and which has already been confirmedby some considerable data (cf. Kornblith 1993). This explanation makesfor such a good example of NE because in this explanation it is tried tounderstand why and how induction is possible on the assumption of alreadygained scientific knowledge (namely the scientific insight into natural kindsand the neo-Darwinistic theory of evolution). And therefore it is also a goodtest case for NE in general.

Quine’s ideas on epistemology seem plausible: if epistemology is notable to deliver the indisputable foundations of the corpus of our knowledge,then it is preferable for epistemology to give up its traditional foundationalendeavour and to aim henceforth at a scientific, i.e., empirically adequatedescription and explanation of scientific knowledge. Although this natu-ralized epistemology no longer gives us any ultimate justification of ourknowledge, it gives us at least a scientific account of the nature, the originand the possibility of scientific knowledge. At least it gives us something– and something is better than nothing.

However, it is still possible to bring forth a very strong argument againstQuine’s defense of NE. It has already been said that Quine bases his defenseof NE on the conviction that FE is impossible. He infers the truth of thisconviction from the failure of the logical empiricist FE. But clearly thisinference is anon sequitur. For from the fact that the logical empiricistversion of FE has failed, it does not follow that every version of FE isdoomed to failure. That is, the failure of logical empiricist FE doesn’trule out the possibility that maybe the neo-Kantian, or the Husserlian, oranother kind of FE will eventually succeed and will give us a foundationaljustification of our knowledge. Quine wrongly neglects this possibilitywhen he concludes to the impossibility of FE on the basis of nothing morethan the failure of the logical empiricist FE. So what is needed for thedefense of NE is a better argument against FE.7

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2. THE MUNCHHAUSEN-TRILEMMA AND APEL’S CRITICISM

Such a better argument against FE has been developed by one of Pop-per’s followers, namely the critical rationalist Hans Albert (1968). Thisargument, which Albert has called “the Munchhausen-Trilemma”, runs asfollows: If one wants to give an indisputable proof (i.e. an ultimate foun-dation) of the truth of some assertion A, that is, if one wants to prove thetruth of A in such a manner that A can no longer be doubted, denied orrefuted, then one has to deduce A in a logically correct way from someindisputable premises, for example P1 and P2. But this proof of A can beindisputable only when the truth of P1 and P2 can also be proved indis-putably. And this requires P1 and P2 to be deduced in a logically correctway from some other indisputable premises, for example P3 and P4, whichalso have to be provided with indisputable proofs,et cetera ad infinitum.Thus one inevitably gets stuck in a potentially infinite regress of proofs.And this regress can only be avoided in two ways:

(1) by means of a circularity in the proof of A (i.e. apetitio principii, ora logical circle), for instance through the presupposition of P1 in theproof of P3 and P4;

(2) or by means of dogmatically stopping the proof of A, for instance byassuming the truth of P3 and P4 without any further argumentation.

In short, if one wants to give an indisputable proof of the truth of someassertion A (or, for that matter, of some belief, hypothesis or theory), thenone inevitably gets stuck in a trilemma. For in developing such a proof oneinevitably gets into one of the following three dead ends:

(1) or one gets into a potentially infinite regress of proofs;(2) or one gets into a logical circle;(3) or one gets into a dogmatic break-off of the proof.

Obviously, each of the horns of this trilemma is fatal to the indisputabilityof the proof of A. From this it clearly follows that indisputable proofsare impossible. But indisputable proofs are essential to FE, since FE aimsat showing the ultimate foundations of the corpus of our knowledge bydeveloping indisputable proofs for the truth of this corpus. Thus it followsthat FE is impossible. Thus the Munchhausen-Trilemma demonstrates theimpossibility of FE (cf. Albert 1968: 13–18).

Albert’s Munchhausen-Trilemma seems to show in an irrefutable man-ner that every kind of FE is doomed to failure. And from this apparentlyinevitable failure of FE it follows that Quine’s NE really seems to be the

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best option for the epistemologist: for if the epistomologist cannot givea foundational justification of the corpus of our knowledge, he can stillaim at giving a scientific explanation of this corpus. However, Karl-OttoApel has made obvious that the Munchhausen-Trilemma is by no meansfatal to FE; moreover, he has even made obvious that the validity of thistrilemma is actually very doubtful. For, as Apel argues, the Munchhausen-Trilemma itself is also based on a premise which is in need of a proof. Thispremise is the presupposition that every successful argumentation, proofor justification has the shape of a logical deduction, that is, of a logicallycorrect inference of conclusions from true premises. If this presuppositionis justified, then the Munchhausen-Trilemma is indeed inevitable. ‘For infact it is a trivial matter to show that an ultimate foundation in the senseof a deduction [..] isn’t possible. And nothing else has been done by K.Popper and H. Albert by using the Friesean trilemma.’ (Apel 1974: 326[my translation]) But according to Apel it is very questionable whetherthis presuppostion is correct. In any case the critical rationalists are notcapable of giving an indisputable proof of the truth of this presupposition,since they believe (on the basis of their own Munchhausen-Trilemma)that indisputable proofs are impossible. That is, if the critical rationalistsshould try to give an indisputable proof of the thesis that every succesfulargumentation, proof or justification has the shape of logical deduction,they would inevitably get stuck in their own trilemma. In this sense, onecan say that the Munchausen-Trilemma is selfdefeating, for it blocks theproof of its own premise (cf. Apel 1976: 64).

Apel has shown that this argument against the Munchhausen-Trilemmacan be applied to every theory in which the possibility of ultimate foun-dation and hence of FE is disputed. For if it is argued in a theory T thatultimate foundations are impossible, then T implies that it is impossibleto give an indisputable proof of the truth of T itself, so that in principle Talways remains doubtful. That is, every theory in which the possibility ofultimate foundations is denied, implies its own unprovability. From this itfollows that it is impossible to prove that ultimate foundations (and henceFE) are impossible. Apel deserves credit for making this clear. So, in fact,Apel falsifies Quine’s defense of NE on the basis of this conviction thatFE is impossible, since Apel shows that it is logically absurd to try toprove that FE is impossible. But it remains questionable whether it followsfrom Apel’s argument that ultimate foundations (and hence FE) are reallypossible. Is Apel capable of saving FE?

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3. APEL AND THE POSSIBILITY OF NON-DEDUCTIVE FOUNDATIONS

From Apel’s critique of the Munchhausen-Trilemma it becomes clear thatthe possibility of ultimate foundations (and hence of FE) can only bemaintained when it is possible to escape from all deductive reasoning,that is, when it is possible to develop a kind of foundation that doesn’tconsist of the logical deduction of conclusions from premises. For onlysuch anon-deductive foundation(“NDF”, for short) won’t be affected bythe Munchhausen-Trilemma.8

Apel is one of those rare contemporary philisophers who still hold on toFE. He wants to maintain the possibility of ultimate foundations and hencehe has tried to develop a kind of NDF. He claims to have found such a NDFin what he calls “transcendental reflection”. According to Apel this tran-scendental reflection is theimmediateinsight (i.e. an insight which is notmediated by reasons) into the necessary, transcendental presuppositionsof all argumentation. This insight arises, says Apel, as soon as those pre-suppositions are denied, doubted or disputed. If one denies or disputes thetruth of those presuppositions, one gets entangled in a self-contradiction,since those presuppositions underlie all kinds of argumentation and hencealso every act of denial, doubt and disputation. That is, if one disputes thetruth of those presuppositions, one disputes what is presupposed by thisvery act of disputation itself which therefore becomes internally inconsis-tent. Next, this contradiction leads to a transcendental reflection on thosetranscendental presuppositions of all argumentation: that is, because ofthis contradiction one immediately knows that those presuppositions can-not possibly be denied or disputed and hence that they are indisputablytrue. Thus one has arrived at an ultimate foundation of those transcenden-tal presuppositions. Apel claims that this foundation is characterized by anon-deductive structure which is instantiated in the immediate insight inthe transcendental presuppositions of all argumentation which is provokedby those self-contradictions.

Apel’s claim that ultimate foundations are possible is based on thepresupposition that the kind of NDF, which he has developed (namelytranscendental reflection), is really possible. Therefore Apel is capableof maintaining the possibility of ultimate foundations only when he canshow this presupposition to be true, that is, when he is able to demonstratethat transcendental reflection is indeed possible. And so Apel is forced togive an argument for the possibility of transcendental reflection. And thisis where Apel gets entangled in difficulties. For he can demonstrate thepossibility of transcendental reflection in only two ways:

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(1) either he defends the possibility of transcendental reflection by meansof arguments which are also based on transcendental reflection;

(2) or he defends the possibility of transcendental reflection by means ofarguments which are not based on transcendental reflection.

It is logically impossible for Apel to have more than these two argumentation-strategies at his disposal. But both strategies lead into trouble:ad (1) If Apel tries to defend the possibility of transcendental reflectionby means of trancendental reflection itself, one may accuse him of beinguncritical. It is true, indeed, that in this case one cannot accuse Apelof being guilty of a logical circle, for then one presupposes that Apel’sargument for the possibility of transcendental reflection is characterizedby a deductive structure, while Apel is trying to avoid such a deductivestructure. But one can reproach Apel with the fact that his argument for thepossibility of transcendental reflection will only be accepted by people whoare already convinced of the possibility of transcendental reflection. In thiscase Apel resembles a spiritistic medium who wards off the question ‘Howdo you know you can talk with ghosts?’ by means of the answer ‘Theghosts have told me so!’. Obviously, this answer will only be acceptedby other spiritistic media; but people who have no special parapsychicpowers will never find this answer very satisfying (or so I hope). Likewise,Apel’s argument for the possibility of transcendental reflection will not beaccepted by someone who has doubted this possibility right from the start.Hence, this argumentation-strategy is useless.ad (2) If Apel tries to defend the possibility of transcendental reflectionby means of arguments which are not based on transcendental reflection,then these arguments will inevitably show a deductive structure. For Apelhas intended his transcendental reflection to be a NDF which escapesfrom the deductive way of argumentation. But if Apel’s arguments forthe possibility of transcendental reflection are characterized by a deductivestructure, then they will inevitably fall prey to the Munchhausen-Trilemma.So this argumentation-strategy is useless as well.

In short, our conclusion must be that Apel isn’t able to develop (bymeans of his notion of transcendental reflection) a kind of NDF with thehelp of which the possibility of ultimate foundations and hence of FE canbe maintained.

It is important to realize that the same argument can be brought forthagainsteveryattempt to maintain the possibility of ultimate foundations(and of FE) by developing a kind of NDF. For if some proponent of FEclaims to have developed a NDF, then he can defend the possibility of thisNDF in only two ways:

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(1) by means of an argument which is based on an NDF itself, but suchan argument isn’t critical;

(2) or by means of an argument which is not based on a NDF, but suchan argument will inevitably have a deductive structure and hence fallprey to the Munchhausen-Trilemma.

Therefore we must conclude that it isn’t possible to defend the possibilityof NDF. So from Apel’s efforts to develop some kind of NDF it becomesobvious that it is not possible to escape from the deductive way of argu-mentation andeo ipsofrom the Munchhausen-Trilemma. This insight mustalso be credited to Apel, although this credit would not be acknowledgedby Apel himself.

4. THE MULTATULI -DILEMMA

At this stage in our argumentation we have ended up in a strange situation,yes even in a dilemma: on the one hand one cannot prove that ultimatefoundations are impossible, but on the other hand one also cannot provethat ultimate foundations are possible. So the only two possible positionswhich can be taken in the discussion about the possibility of ultimatefoundations and FE are both equally untenable. Why? Let me sum up thelast two sections:(Section 2) If one argues for the thesis that ultimate foundations are impos-sible, then this thesis implies the unprovability of this very same thesis.(section 3) If on argues that ultimate foundations are possible all the same,then one has to demonstrate the possibility of NDF, or else one succumbsto the Munchhausen-Trilemma; but it turns out to be impossible to provethat NDF is possible.

In short, we have to assert that no assertion, theory or belief can begiven an indisputable proof, not even this assertion itself. The Dutch writ-er Multatuli approximated this dilemma – without any knowledge aboutphilosophical theories on ultimate foundations – when he wrote: ‘Maybenothing is totally true and not even this’.9 Therefore I want to baptize thisdilemma as the “Multatuli-dilemma”.

This Multatuli-dilemma demonstrates that there is no solution to theproblem of the possibility of ultimate foundations and hence of FE. And aproblem that cannot be solved is best seen as a non-problem or a pseudo-problem. Because of this dilemma we cannot give a definite answer to thequestion whether ultimate foundations are possible or not. And it is muchbetter not to ask any unanswerable questions. Therefore the discussionabout the possibility or impossibility of FE is in vain, that is, it is a discus-

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sion without any prospect to a solution and thus not a real discussion. Andso this dilemma relieves us of the duty to philosophize any longer aboutthe possibility of ultimate foundations and of FE. That is, it allows us todirect our philosophical attention and energies to other problems which dohave a chance of being solved. So now nothing seems to be in the wayof following Quine in supporting NE. Of course, Quine’s thesis on theimpossibility of FE has been refuted by Apel, but that certainly doesn’timply that FE is possible. Rather, it turned out that the discussion aboutultimate foundations and FE is useless. The wisest thing to do, therefore,is to divorce epistemology from all foundational desires and to naturalizeit, as Quine has urged us to do. That is, since the problem of the possibilityof FE has been exposed as a pseudo-problem, replacement of FE by NEhas become the only wise option.

5. NE AND RADICAL SCEPTICISM

But is it really true that Quine is right when he says that the wisest thingto do after the drop-out of FE is to propagate NE? Is it really true thatNE is the best option after the downfall of the epistemological search forultimate foundations? The driving force behind FE was fear of radical,epistemological scepticism: the proponents of FE feared that the body ofour knowledge should be distrusted, yes even abandoned if it should turnout to be impossible to provide that body with indisputable foundations.Isn’t it inevitable that one succumbs to this radical scepticism when onedivorces epistemology from all foundational desires and integrates it in thescientific body?

Indeed so it is, says Barry Stroud (1984: 209–254) in his criticism ofQuine’s NE. To defend this belief Stroud uses one of Quine’s own argu-ments, namely his underdeterminacy argument. According to this argu-ment, empirically equivalent theories can still be logically incompatiblewith one another, so that it is impossible to know on the basis of empir-ical data which of many empirically equivalent theories is closest to thetruth or is in most agreement with reality (cf. Quine 1975a). According toStroud, this indeterminacy argument inevitably leads to a radical scepticismwith respect to the possibility of science in general (cf. Stroud 1984: 233).Stroud argues that Quine isn’t able to refute this scepticism by means of NEbecause of the fact that NE is part of the scientific corpus and is thereforealso affected by this scepticism. So if Quine tries to refute this sceptisismwith the help of NE, he will get entangled in a logical circle, since he isthen trying to refute scepticism by means of something which is also underthe scepticist’s suspicion, or so Stroud claims. Therefore Stroud (1984:

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222) makes the following remark about Quine’s attempt to make plausiblethe possibility of induction with the help of scientific means: ‘Even if wecould explain “scientifically” why we make the kinds of inferences wedo, it would not follow that we had answered the traditional “doctrinal”question of whether the conclusions of our inferences are justified by theirpremises. That is because the scientific information we appeal to in ourexplanation would itself have been arrived at by just such an inference.’

Quine, on the other hand, argues that it is not at all circular to fightscepticism by means of NE. For according to Quine science itself showsthat all our knowledge arises from sensory data and that these data don’tconstitute a sufficient ground for the possible truth of our knowledge.Thus it is an empirical, intra-scientific fact that our theories are radicallyunderdetermined by all empirical data: ‘It is thus our very understandingof the physical world, fragmentary though that understanding be, thatenables us to see how limited the evidence is on which that understandingis predicated.’ (Quine 1976c: 229) From this Quine concludes that thesceptical problem is a scientific problem, i.e. a problem that arises withinscience and which therefore can be solved by scientific means, that is,by means of NE. So Stroud’s claim that it is circular to fight scepticismthrough NE is unjustified: ‘... the sceptical challenge springs from scienceitself and ... in coping with it we are free to use scientific knowledge.’(Quine 1974: 3) The naturalistic epistemologist is someone who takesscience in protection against itself, who tries to protect science against thesceptical doubts that arise from within science: ‘The epistemologist thusemerges as a defender or protector ... he is out to defend science fromwithin, against its selfdoubts.’ (Ibidem)

Stroud is not impressed by this argument of Quine’s. He actuallybelieves that Quine’s argument amounts to areductio ad absurdumofthe possibility of science. For if science itself shows the radical empiricalunderdetermination of our theories, that is, if science itself is the generatorof the sceptical distrust of science, as Quine emphasizes, then science hasdemonstrated its own impossibility.10 So, according to Stroud, from thefact that scepticism is a product of science it doesn’t follow that it is allowedto fight scepticism with scientific means, that is, by means of NE; on thecontrary, from this fact it follows that science has demonstrated its own(and hence NE’s) impossibility. In this vein Stroud (1984: 229) remarks:‘If I am right, the fact that “sceptical doubts are scientific doubts” does notput the epistemologist who raises such doubts in the stronger position ofbeing free to use scientific knowledge of the world in his effort to answerthose doubts and explain how knowledge is possible.’

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Stroud’s argument against Quine’s NE seems to be successful, partlybecause Quine himself admits that the scientific origin of the scepticaldoubts can be conceived of as some kind of self-refutation of science: ‘I amnot accusing the sceptic of begging the question; he is quite within his rightsin assuming science in order to refute science; this, if carried out, wouldbe a straightforward argument byreductio ad absurdum.’ (Quine 1975b:68) But, for all that, Stroud’s argument isn’t sound. Stroud presupposesthat Quine really wants to refute radical scepticism by means of NE, butactually that is not not Quine’s aim. The attempt to refute scepticism isidentical to the attempt to prove that it is possible to have true knowledgeof reality on the basis of empirical data, and this attempt is characteristicfor FE. But Quine has already left behind him all foundational strivings ofFE, because he takes FE to be untenable. Therefore Quine no longer aimsat refuting scepticism by means of NE. Thus Stroud’s argument againstQuine’s NE is unjustified.

But if Quine has no intention of refuting scepticism by means of NE,then he seems to have no defense whatsoever against scepticism. That is,then it seems inevitable that the whole scientific corpus – including Quine’sNE – must fall prey to the sceptical doubts. So, in a sense, Stroud is rightafter all?

The asnwer to this question must be: No. For scepticism has lost itsrelevance too after the downfall of FE, as Quine has made clear. The drivingforce behind FE was fear of scepticism. But, according to Quine, this fearis unjustified. Scepticism doesn’t constitute a real threat against our faithin science. For scepticism demands something of us which is practicallyimpossible; it demands that we question the set of our beliefs as a whole,i.e. the whole body of our knowledge. But we cannot possibly do that.For we have no certainty whatsoever, i.e. not a single cognitive handholdoutside the body of our knowledge. And therefore radical scepticism, whichdoubts all our knowledge, hasn’t got any firm ground to stand on. This iswhy Quine (1976b: 65) says: ‘We have to work within some conceptualscheme or other; we can switch schemes, but we cannot stand apart fromall of them.’ We cannot examine from some transcendent God’s point ofview whether or not our knowledge is in agreement with reality, sincesuch a lofty point of view has also become untenable with the downfallof FE. The sceptic, however, imagines to be doing just that: looking atthe body of our knowledge from such a God’s point of view. But thatis just megalomania. ‘What evaporates is the transcendental question ofthe reality of the external world – the question whether or in how far ourscience measures up to theDing an sich.’ (Quine 1981a: 22) In short,although FE and radical scepticism are each other’s antipodes, they share a

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common premise all the same, namely the presupposition that it is possibleto examine the corpus of our knowledge from the outside, that is, from someGod’s point of view. But we just are not able to do that and therefore bothFE and radical scepticism have become untenable and irrelevant.Maybescepticism could be right. But that cannot have any effect on our attitudetowards our beliefs, since those beliefs are the only cognitive foothold wehave. Thus Quine (1981b: 475) says: ‘... my only criticism of the sceptic isthat he is overreacting.’ Expressed in terms of Neurath’s metaphor: maybethe ship in which we sail is defective and maybe it even makes waterbecause of leaks, but, alas, it is the only ship we have got. We cannot – inthe open sea – step over to some other ship. Thus the only thing we cando, is improve the ship while we are sailing on it: we must make shift withwhat we already have. The scepticist throws himself overboard because hedoesn’t trust the ship to be seaworthy and consequently he drowns, whileat the same time the naturalist tries to stay alive by keeping the ship afloatat all costs.11

In short, although NE is not able to refute radical scepticism, NE hasnothing to fear from this scepticism, since radical scepticism, which doubtsall our knowledge, is practically impossible.

6. NE AND THE JUSTIFICATION OF METHODOLOGICAL NORMS

Thus in practice Quine’s replacement of FE by NE does not lead to radicalscepticism. But it is still possible to bring forth another argument againstQuine’s thesis that FE should be replaced by NE; this argument has beendeveloped by Henri Lauener (1982, 1990) among other philosophers.12

It goes like this: It is useless to replace FE by NE because of the factthat NE is not able in principle to fulfil the most important one of all theepistemological tasks, namely the justification of methodological norms,i.e. the proving of prescriptive assertions about which methods one mustuse in science in order to achieve true or empirically adequate knowledge.If NE isn’t capable of fulfilling this pre-eminently epistemological task,then there is no point in calling it “epistemology”, because then it does-n’t distinguish itself in any way from something like ordinary cognitivepsychology.

Why does Lauener say that NE isn’t able to justify methodologicalnorms? In the first place – Lauener argues – NE commits a naturalisticfallacy when it tries to justify methodological norms, for then it tries to inferprescriptive assertions about scientific methods from descriptive assertionsabout the nature and origin of our knowledge: ‘One could, parodying Hume,ask how the naturalist starting from the first descriptive thesis (from “is”)

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arrives at the normative thesis (the “ought”)?’ (Lauener 1982: 126 [mytranslation]) In the second place – Lauenerargues in agreement with Stroud– NE is guilty of a logical circle when it tries to justify methodologicalnorms, because NE is an integral part of the scientific corpus and thereforeit uses the very same methods it is trying to justify. Therefore Lauener(1990: 214) makes the following remark about Quine: ‘ ...he finds himselfthreatened by circularity because of his propensity to justify the scientist’sacceptance of theories by strictly intrascientific arguments.’

Lauener’s criticism of NE seems to get confirmation from Quine himselfwho admits that NE can justify methodological norms only on penaltyof circularity. For Quine states that his explanation of the possibility ofinduction should not be seen as a justification of induction qua scientificmethod: “I am not appealing to Darwinian biology to justify induction.This would be circular, since biological knowledge depends on induction.Rather I am granting the efficacy of induction, and then observing thatDarwinian biology, if true, helps explain why induction is as efficious as itis.” (Quine 1975b: 70) In short, Lauener’s criticism of Quine’s replacementof FE by NE seems to be correct: Only FE would be capable of justifyingmethodological norms, for only FE would be able to infer such normsfrom necessary principles which would be justified independently of thescientific corpus. Thus normative methodology too has disappeared withthe down fall of FE. But an epistemology like NE, which is not capable ofnormative methodology, really is not epistemology after all. And thereforeit is useless to replace FE by NE, or so Lauener concludes.

However, this conclusion is at odds with what Quine explicitly statesabout methodological norms. For according to Quine, NE is capable of jus-tifying methodological norms all the same. This is why Quine (1990: 19)makes the following remark about critics like Lauener: ‘ ...they are wrongin protesting that the normative element, so characteristic of epistemology,goes by the board.’ Quine explicitly states that NE is able to designatescientific methods which are more reliable and thus lead to more adequatehypotheses than other methods: ‘ ...naturalized epistemology on its nor-mative side is occupied with heuristics generally – with the whole strategyof rational conjecture in the framing of scientific hypotheses.’ (Idem: 20)How can these statements be reconciled with Quine’s earlier statement,quoted above, in which he denies that his explanation of the possibilityof induction can be seem as a methodological justification of induction?Does Quine contradict himself or is it possible to save the consistency ofhis statements in any way?

Yes, it is possible to reconcile all of Quine’s statements about the justi-fication of methodological norms with each other. What is needed here is a

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distinction between two kinds of methodological justification: we have todistinguishexternaljustifications on the hand frominternal justificationson the other. In the case of an external justification of a methodologicalnorm, what is at issue is an ultimate foundation (i.e. an indisputable proofof the validity) of that norm: one searches for an indisputable principleoutside the scientific corpus and then one tries to prove that norm on thebasis of this principle. Obviously, this kind of justification has becomeimpossible with the downfall of FE. But in the case of an internal justifica-tion of a methodological norm, what is at issue is ajustification immanentto the body of scientific knowledge: some scientific method gets justifiedon the basis of an empirically adequate explanation of the success of thismethod. On the basis of scientific knowledge, which has already beenachieved, one explains why some method leads to true or empirically ade-quate knowledge. Then, because of this explanation, this method becomesa methodological norm. It is, of course, obvious that NE is very suitablefor giving such internal justifications of methodological norms. A strikingexample of such an internal justification is delivered by Quine’s explana-tion of the possibility of induction: if this explanation doesn’t get falsifiedand gets confirmed by more and more data, then induction will be justi-fied as a scientific method on the basis of scientific knowledge which hasalready been achieved. Another example of such an internal justificationis Quine’s justification of what is in his viewthe most notable norm ofnaturalized epistemology, namely the norm that all knowledge of realityshould be obtained through the senses: ‘This is a prime specimen of nat-uralized epistemology for it is a finding of natural science about scienceitself, however fallible, that our information about the world comes onlythrough impacts on our sensory receptors. And still the point is normative,warning us against telepaths and soothsayers.’ (Quine 1990: 19)

So now the consistency of Quine’s statements about methodologicaljustification, quoted above, can be saved: Quine’s statement that his expla-nation of the possibility of induction isn’t a justification of induction, canbe interpreted as meaning that this explanation should not be seen as anexternal justificationof induction. At the same time this interpretationimplies that NE is capable of normative methodology after all, namely inthe shape ofinternal justificationsof methodological norms.

However, one could ask whether external justifications should not bepreferred to internal justifications. For isn’t it obvious that radical scepti-cism can only be fought by means of external justifications of scientificmethods? Since internal justifications, forming an integral part of the sci-entific corpus, are also affected by this scepticism, they are of no avail

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in the fight against radical scepticism. External justifications don’t sufferfrom such problems.

Nevertheless, external justifications are superfluous. Such justificationsare needed only when radical scepticism constitutes a real threat, i.e. whenthe absence of ultimate foundations actually leads to a scepticist rejectionof the possibility of science. But from the preceding consideration ofStroud’s criticism of NE it has become clear that radical scepticism isabsurd, i.e. practically impossible and therefore it constitutes no real threatto science. Thus the need for external justifications of methodologicalnorms also disappears. An internal justification is justification enough.And methodology on the basis of NE is methodology enough.

But can Lauener’s arguments against the possibility of normative method-ology on the basis of NE not also be applied to these so-called internaljustifications?

In the first place, isn’t it inevitable that every internal justification ofa methodological norm is guilty of a naturalistic fallacy? The answermust be: No! For the methodological norms which NE justifies throughinternal justifications, aren’t identical to prescriptive statements (i.e. ought-sentences). These norms are nothing but a kind of descriptive statements,namely conditional statements: if one wants to attain A, then one has todo B. What such a norm actually says is this: if one wants to reach trueor empirically adequate knowledge about this-or-that object, then one hasto use this-or-that method. Such statements are normative, since they saywhat onemustdo under certain circumstances. But they are not prescrip-tive, since the antecedent of the conditional doesn’t express an obligationor something like that; that is, one is of course allowed not to strive at trueor empirically adequate knowledge, but then one just stops doing science.In short, it is not the case that in an internal justification anoughtis derivedfrom anis.

In the second place, isn’t it inevitable that internal justifications areguilty of logical circles? For when a method gets justified internally onthe basis of scientific knowledge which has been gained by means of thisvery same method, isn’t it obvious then that this justification is circularand hence logically invalid? The answer must once again be: No! For thecertainty which is pursued in an internal justification, is never any biggerthan the certainty which one already has. This is why Quine (1990: 19) says:‘I am of that large minority or small majority who repudiate the Cartesiandream of a foundation for scientific certainty firmer than the scientificmethod itself.’ By means of internal justifications one demonstrates thatthe corpus of our knowledge is internally consistent and coherent, and thatthe possibility of scientific knowledge is guaranteed by this very same

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knowledge. Through internal justifications the corpus of our knowledge issecured from within. The sceptical doubts, which arise within science itself,are refuted by these internal justifications. Thus these internal justificationsconstitute the task of the epistemologist as Quine (1974: 3) envisages him:‘The epistemologist thus emerges as a defender or protector: he no longerdreams of a first philosophy, firmer than science, on which science canbe based, he is out to defend science from within, against its self-doubts.’In short, the task of the epistemologist consists in plugging the leaks inNeurath’s ship.

7. SUMMARY AND CONCLUSIONS

In this paper I examined the question whether FE can be replaced by NE,that is, whether it is possible to divorce epistemology from all traditionalfoundational desires and to integrate it in the corpus of scientific knowl-edge. For this reason I tried to answer the following questions:

(1) Is it justified to claim (as Quine does) that FE is impossible anddestined to fail?

(2) Is it justified to conclude (as Quine does) from the eventual failure ofFE that epistemology should be naturalized, that is, that FE should bereplaced by NE?

ad (1) It turned out that Quine’s defense of NE is insufficient. Quine groundshis defense of NE on the conviction that FE is impossible. However, forQuine “FE” exclusively designates the logical empiricist FE of Carnap andthe failure of this version of FE doesn’t imply that all other versions (suchas the Kantian or the Husserlian versions) of FE are doomed to failureas well. So if one wants to defend NE, one needs a better argument forthe impossibility of FE. This argument can be found in the Munchhausen-Trilemma of the critical rationalist Hans Albert: this trilemma impliesthat ultimate foundations (and hence FE) are impossible. However, Karl-Otto Apel has criticized the Munchhausen-Trilemma by demonstratingthe absurdity of trying to prove the thesis that ultimate foundations areimpossible. For if this thesis is true, then the truth of this very same thesiscan never be proved in an undisputable manner. Next, Apel’s criticism of theMunchhausen-Trilemma showed that ultimate foundations are attainableonly if it is possible to develop a kind of NDF. But it turned out to beunattainable to develop any NDF. All this implies a dilemma which I havecalled “the Multatuli-dilemma”: on the one hand it is absurd to try to provethat ultimate foundations are impossible, but on the other hand it is also

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impossible to prove that ultimate foundations are possible. This Multatuli-dilemma demonstrates that the discussion about the possibility of FE isuseless. In this sense we have to conclude that FE is doomed to failure.ad (2) The question whether one may conclude from the failure of FE thatFE should be replaced by NE, was subdivided into two other questions:

(a) Barry Stroud argues that replacement of FE by NE leads inevitablyto radical scepticism concerning the possibility of science. Is Stroudright? No, for radical scepticism turned out to be practically impossi-ble, and hence scepticism constitutes no threat to NE.

(b) Henri Lauener argues that NE isn’t capable of normative methodol-ogy, although normative methodology is essential to epistemology.Is Lauener right? No, because NE is able to justify methodologi-cal norms, contrary to what Lauener maintains. But this only bearson so-calledinternal justifications, that is, justifications of scientificmethods by means of scientific explanations of the success of thosemethods. It appears that these internal justifications are neither guiltyof naturalistic fallacies, nor of logical circles.

In short, the conclusion of this paper must be that FE is untenable andshould therefore be replaced by NE.

NOTES

1 The nature and rise of FE are described very adequately in: Richard Rorty,Philosophyand the mirror of nature, Oxford 1980.2 Cf. Kornblith 1985 and 1993. See also: P. Kitcher, “The naturalist return”, in: ThePhilosophical Review, vol. 101, no. 1, 1992. And also: A Rosenberg, “A field guide torecent species of naturalism”, in: The British Journal for the Philosophy of Science, 47,996, 1–29.3 This also becomes clear in the representation of Quine’s defense of NE in: N. Everitt andA. Fisher,Modern epistemology: A new introduction, New York 1995, 180.4 Cf. “If epistemology is denied the status of a branch of learning which is prior to scienceand which has to provide a foundation for science, is it condemned to disappear, shortof having a legitimate subject-matter? Quine’s reply is well-known: epistemology shouldnot disappear like astrology or alchemy, it should go on but in a new setting: the task ofjustifying the step from sense-data to belief in the existence of the past, other minds orphysical things is replaced by that of explaining how the stimulation of our nerve endingsresults, as output, into a description of the three-dimensional external world and its history.”(Gochet 1995: 125)5 Cf. “But as a medium for such epistemological inquiry we can choose no better than theselfsame world theory which we are trying to prove, this being the best available at the time.”(Quine 1976a: 254) Cf. “If we are out simply to understand the link between observationand science, we are well advised to use any available information, including that provided

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by the very science whose link with observation we are seeking to understand.” (Quine1969a: 76)6 Cf. “The survival value of primitive induction is anticipation of something edible, or ofsome creature by which one might be eaten. Thus it is that natural selection has endowed uswith standards of perceptual similarity that mesh pretty well with natural trends, affordingus better than random success in our expectations. Thus it is that induction has been servingus and other animals so well.” (Quine 1995: 19–20)7 A similar argument against Quine’s defense of NE can be found in: Robert Almeder, “Onnaturalizing epistemology”, in: American Philosophical Quarterly, vol. 27, no. 4, 1990,263–279.8 Obviously, such a non-deductive foundation can not be conceived of as induction orabduction. For, of course, ultimate foundations cannot be attained through either inductionor abduction.8 Multatuli [= Eduardo Douwes-Dekker]Ideen, Amsterdam 1872 bundel 1, 1ste idee [mytranslation].Original: Misschien is niets geheel waar, en zelfs dat niet.10 Cf. “The reductio ad absurdumwould presumably run something like this. Either scienceis true and gives us knowledge or it does not. If it is not true, nothing we believe about thephysical world amounts to knowledge. But if it does give us knowledge, we can see fromwhat it tells about the meagre impacts at our sensory surfaces during perception that wecan never tell whether the external world really is the way we perceive it to the be. But ifthat is so, we can know nothing about the physical world. So once again nothing we believeabout the physical world amounts to knowledge.” (Stroud 1984: 228)11 This interpretation of the relation between Quine’s naturalism and Stroud’s scepticismis also advocated by Christopher Hookway. Cf. ‘We cannot step off the boat, abandoningour scientific picture of the world while retaining a grip on “reality” which can be used toraise epistemological questions... We have abandoned the metaphysical framework whichgave the Cartesian challenges their philosophical force.’ (Chr. Hookway,Quine: Language,experience and reality, Oxford 1988: 198.) See also: R. F. Gibson, ‘Stroud on naturalizedepistemology’ in: Metaphilosophy, vol. 20, no. 1, 1989: 9.12 The same argument can be found in: Jaegwon Kim, “What is “Naturalized Epistemol-ogy”?”, in: Philosophical Perspectives 2, 1988, 381–405. See also: Alvin I. Goldman,Epistemology and cognition, Cambridge/Mass. and London 1986, 2. Stroud (1984: 220)too argues along these lines. Finally, see also: Harvey Siegel, “Justification, Discovery andthe Naturalizing of Epistemology”, in: Philosophy of Science, 47, 1980, 287–321.

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