Luca Moretti -- Research

In this paper I focus on a key argument for global scepticism resting on the underdetermination thesis according to which we cannot know any proposition p about our immediate physical world because any empirical evidence for p equally supports some sceptical scenario sk alternative to and incompatible with p (e.g. the Cartesian demon scenario). My central claim is conditional: I contend that the underdetermination argument can go through only if the controversial thesis that conceivability (or an akin a priori faculty) is a guide to metaphysical possibility is true. I also suggest a general reason to disbelieve this thesis and to reject the underdetermination argument. My analysis makes a crucial use of a Bayesian model of learning that employs fuzzy probabilities.

"Moore’s Proof and Epistemic Closure" (co-authored with Tomoji Shogenji, submitted)

In this paper we address the issue of epistemic closure with particular attention to Moore’s controversial proof of the existence of the material world. Moore’s proof infers that (M) there is a material world from the premise that (H) there is a hand, when the latter appears justified by (E) the sense experience of a hand. Our goal is to reconcile three seemingly incompatible intuitions about Moore’s proof. First, that we are justified to believe H given E. Second, that we are not justified to believe M given E. Third, that we are allowed to expand our body of justified beliefs through logical entailment. We propose to reconcile these three claims by a Bayesian model according to which justification has two divergent goals: to increase true beliefs while avoiding false beliefs. This model offers an alternative to the familiar but questionable view that justification is sufficiently high probability. Our investigation sheds new lights on both closure of justification and transmission of justification under known entailment.

"Wright, Okasha and Chandler on transmission failure" (forthcoming in Synthese)

Crispin Wright has given an explanation of how a first time warrant can fall short of transmitting across a known entailment. Formal epistemologists have struggled to turn Wright’s informal explanation into cogent Bayesian reasoning. In this paper, I analyse two Bayesian models of Wright’s account respectively proposed by Samir Okasha and Jake Chandler. I argue that both formalizations are unsatisfactory for different reasons, and I lay down a third Bayesian model that appears to me to capture the valid kernel of Wright’s explanation. After this, I consider a recent development in Wright’s account of transmission failure. Wright suggests that his condition sufficient for transmission failure of first time warrant also suffices for transmission failure of supplementary warrant. I propose an interpretation of Wright’s suggestion that shields it from objections. I then lay down a fourth Bayesian framework that provides a simplified model of the unified explanation of transmission failure envisaged by Wright.

"Ways in which coherence is confirmation conducive" (published in Synthese 157(3), 2007, pp. 307-317)

Recent works in epistemology show that the claim that coherence is truth conducive – in the sense that, given suitable ceteris paribus conditions, more coherent sets of statements are always more probable – is dubious and possibly false. From this, it does not follows that coherence is a useless notion in epistemology and philosophy of science. Dietrich and Moretti (2005) have proposed a formal of account of how coherence is confirmation conducive – that is, of how the coherence of a set of statements facilitates the confirmation of such statements. This account is grounded in two confirmation transmission properties that are satisfied by some of the measures of coherence recently proposed in the literature. These properties explicate everyday and scientific uses of coherence. In his paper, I review the main findings of Dietrich and Moretti (2005) and define two evidence gathering properties that are satisfied by the same measures of coherence and constitute further ways in which coherence is confirmation conducive. At least one of these properties vindicates important applications of the notion of coherence in everyday life and in science.

"Probabilistic Measures of Coherence and the Problem of Belief Individuation" (co-authored with Ken Akiba, published in Synthese 154(1), 2007, pp. 73-95)

Coherentism in epistemology has long suffered from lack of formal and quantitative explication of the notion of coherence. One might hope that probabilistic accounts of coherence such as those proposed by Lewis, Shogenji, Olsson, Fitelson, and Bovens and Hartmann will finally help solve this problem. This paper shows, however, that those accounts have a serious common problem: the problem of belief individuation. The coherence degree that each of the accounts assigns to an information set (or the verdict it gives as to whether the set is coherent tout court) depends on how beliefs (or propositions) that represent the set are individuated. Indeed, logically equivalent belief sets that represent the same information set can be given drastically different degrees of coherence. This feature clashes with our natural and reasonable expectation that the coherence degree of a belief set does not change unless the believer adds essentially new information to the set or drops old information from it; or, to put it simply, that the believer cannot raise or lower the degree of coherence by purely logical reasoning. None of the accounts in question can adequately deal with coherence once logical inferences get into the picture. Toward the end of the paper, another notion of coherence that takes into account not only the contents but also the origins (or sources) of the relevant beliefs is considered. It is argued that this notion of coherence is of dubious significance, and that it does not help solve the problem of belief individuation.

"The Tacking by Disjunction Paradox: Bayesianism versus Hypothetico-deductivism" (published in Erkenntnis 64(1), 2006, pp. 115-138)

Hypothetico-deductivists have struggled to develop qualitative confirmation theories not raising the so-called tacking by disjunction paradox. In this paper, I analyze the difficulties yielded by the paradox and argue that the hypothetico-deductivist solutions given by Gemes (1998) and Kuipers (2000) are questionable because they do not fit such analysis. I then show that the paradox yields no difficulty for the Bayesian who appeals to the Total Evidence Condition. I finally argue that the same strategy is unavailable to the hypothetico-deductivist.

"On coherent sets and the transmission of confirmation" (co-authored with F. Dietrich, published in Philosophy of Science 72(3), 2005, pp. 403-424)

In this paper, we identify a new and mathematically well-defined sense in which the coherence of a set of hypotheses can be truth-conducive. Our focus is not, as usually, on the probability but on the confirmation of a coherent set and its members. We show that, if evidence confirms a hypothesis, confirmation is “transmitted” to any hypotheses that are sufficiently coherent with the former hypothesis, according to some appropriate probabilistic coherence measure such as Olsson’s or Fitelson’s measure. Our findings have implications for scientific methodology, as they provide a formal rationale for the method of indirect confirmation and the method of confirming theories by confirming their parts.

"Defusing the conditional fallacy: a semantical approach" (co-authored with Patrick Girard, submitted)

The conditional fallacy is an argument deemed to entail absurd consequences for notions defined in terms of counterfactuals. For instance, the antirealist notion of truth is typically defined in the terms of what a rational thinker would believe if she were suitably informed. This notion is deemed to entail, through the conditional fallacy, the absurdity that there is necessarily a rational thinker. If this were the case, alethic antirealism should probably be rejected. In this paper we analyse the conditional fallacy from a semantical (i.e. model-theoretic) point of view. This allows us to identify with precision the philosophical commitments that ground the validity of this argument. We show that the conditional fallacy is generally valid only if some non-compulsory and questionable metaphysical assumptions are accepted. We suggest that the antirealist is not committed to the conditional fallacy because she is not committed to some of these assumptions. Though we focus primarily on alethic antirealism, our analysis generalises to other philosophical uses of the conditional fallacy.

"Logical Pluralism is compatible with monism about metaphysical modality" (co-authored with Nicola Ciprotti, published in the Australasian Journal for Philosophy 87(2), pp. 275-284)

Beall and Restall (2000), (2001) and (2006) advocate a comprehensive pluralist approach to logic, which they call Logical Pluralism, according to which there is not one true logic but many equally acceptable logical systems. They maintain that Logical Pluralism is compatible with monism about metaphysical modality, according to which there is just one correct logic of metaphysical modality. Wyatt (2004) contends that Logical Pluralism is incompatible with monism about metaphysical modality. We first suggest that if Wyatt were right, Logical Pluralism would be strongly implausible because it would get upside down a dependence relation that holds between metaphysics and logic of modality. We then argue that Logical Pluralism is prima facie compatible with monism about metaphysical modality.

"The ontological status of minimal entities" (published in Philosophical Studies 141(1), pp. 97-114)

Minimal entities are, roughly, those that fall under notions defined by only deflationary principles. In this paper I provide an accurate characterization of two types of minimal entities: minimal properties and minimal facts. This characterization is inspired by both Schiffer’s notion of a pleonastic entity and Horwich's notion of minimal truth. I argue that we are committed to the existence of minimal properties and minimal facts according to a deflationary notion of existence, and that the appeal to the inferential role reading of quantifiers does not dismiss this commitment. I also argue that deflationary existence is language-dependent existence – this clarifies why minimalists about properties and facts are not realists about these entities though their language may appear indistinguishable from the language of realists.

"Brogaard and Salerno on antirealism and the conditional fallacy" (published in Philosophical Studies 140(2), 2008, pp. 229-246)

Brogaard and Salerno (2005) have argued that antirealism resting on a counterfactual analysis of truth is flawed because it commits a conditional fallacy by entailing the absurdity that there is necessarily an epistemic agent. Brogaard and Salerno’s argument relies on a formal proof built upon the criticism of two parallel proofs given by Plantinga (1982) and Rea (2000). If this argument were conclusive, antirealism resting on a counterfactual analysis of truth should probably be abandoned. I argue however that the antirealist is not committed to a controversial reading of counterfactuals presupposed in Brogaard and Salerno’s proof, and that the antirealist can in principle adopt an alternative reading that makes this proof invalid. My conclusion is that no reductio of antirealism resting on a counterfactual analysis of truth has yet been provided.

"A thick realist consequence of Wright’s minimalism" (published in the Pacific Philosophical Quarterly 88(1), 2007, pp. 24-38)

According to Wright’s minimalism, a notion of truth neutral with respect to realism and antirealism can be built out of the notion of warranted assertibility and a set of a priori platitudes among which the Equivalence Schema has a prominent role. Wright believes that the debate about realism and antirealism will be properly and fruitfully developed if both parties accept the conceptual framework of minimalism. In this paper, I show that this conceptual framework commits the minimalist to the realist thesis that there are mind-independent propositions; with the consequence that minimalism is not neutral to realism and antirealism. I suggest that Wright could avert this conclusion if he rejected the customary interpretation of the Equivalence Schema according to which this Schema applies to propositions. This would however render minimalism unpalatable to philosophers who welcome the traditional reading of the Equivalence Schema and believe that propositions are bearers of truth.