«Mettre les faits d’accord avec la philosophie de Platon»: voilà une maxime qui remonte au Commentaire de Proclus au premier livre des Éléments d’Euclide, oeuvre centrale pour la constitution du savoir au Cinquecento et plus particulièrement pour la définition du statut opératoire des mathématiques. Au cours du XVIe siècle, Euclide apparaît en effet comme le véritable médiateur entre platonisme et aristotélisme, au demeurant moins par son oeuvre de géomètre que par son geste épistémologique qui semble tracer l’unique voie possible pour (...) accéder à la connaissance de toutes les choses, soit sensibles soit métaphysiques. Les interprétations de Jacopo Mazzoni ("In universam Platonis et Aristotelis philosophiam praeludia, sive de comparatione Platonis et Aristotelis", 1597) et de Francesco Barozzi ("Opusculum, in quo una oratio, et duae quaestiones: Altera de certitudine, et altera de medietate mathematicarum continentur", 1560), que j’examine dans mon article, offrent deux perspectives différentes, qui redonnent une actualité philosophique au néoplatonisme mathématique de Proclus. (shrink)

Since Benacerraf’s “Mathematical Truth” a number of epistemological challenges have been launched against mathematical platonism. I first argue that these challenges fail because they unduely assimilate mathematics to empirical science. Then I develop an improved challenge which is immune to this criticism. Very roughly, what I demand is an account of how people’s mathematical beliefs are responsive to the truth of these beliefs. Finally I argue that if we employ a semantic truth-predicate rather than just a deflationary one, there surprisingly (...) turns out to be logical space for a response to the improved challenge where no such space appeared to exist. (shrink)

The tenor of much recent work in the philosophy of mathematics has been dictated by the popular assumption that Platonism is defunct. Some embrace that assumption and look for alternatives, others deny it and attempt to revive Platonism, but either way it is the starting point. The fate of Platonism took center stage with the appearance of Paul Benacerraf’s “Mathematical truth”, but a decade has passed since then, and the philosophical climate has changed. Most important, the quarter from which Platonism (...) was to receive its mortal wound—epistemology—has developed considerably; the epistemological theory presupposed by Benacerraf is no longer popular. This makes it difficult to assess the value of work in the philosophy of mathematics done under the influence of Benacerraf’s formulation. (shrink)

Philosophers of mathematics agree that the only interpretation of arithmetic that takes that discourse at 'face value' is one on which the expressions 'N', '0', '1', '+', and 'x' are treated as proper names. I argue that the interpretation on which these expressions are treated as akin to free variables has an equal claim to be the default interpretation of arithmetic. I show that no purely syntactic test can distinguish proper names from free variables, and I observe that any semantic (...) test that can must beg the question. I draw the same conclusion concerning areas of mathematics beyond arithmetic. This paper is a greatly extended version of my response to Stewart Shapiro's paper in the conference 'Structuralism in physics and mathematics' held in Bristol on 2–3 December, 2006. (shrink)

Modern philosophy of mathematics has been dominated by Platonism and nominalism, to the neglect of the Aristotelian realist option. Aristotelianism holds that mathematics studies certain real properties of the world – mathematics is neither about a disembodied world of “abstract objects”, as Platonism holds, nor it is merely a language of science, as nominalism holds. Aristotle’s theory that mathematics is the “science of quantity” is a good account of at least elementary mathematics: the ratio of two heights, for example, is (...) a perceivable and measurable real relation between properties of physical things, a relation that can be shared by the ratio of two weights or two time intervals. Ratios are an example of continuous quantity; discrete quantities, such as whole numbers, are also realised as relations between a heap and a unit-making universal. For example, the relation between foliage and being-a-leaf is the number of leaves on a tree,a relation that may equal the relation between a heap of shoes and being-a-shoe. Modern higher mathematics, however, deals with some real properties that are not naturally seen as quantity, so that the “science of quantity” theory of mathematics needs supplementation. Symmetry, topology and similar structural properties are studied by mathematics, but are about pattern, structure or arrangement rather than quantity. (shrink)

This rich book differs from much contemporary philosophy of mathematics in the author’s witty, down to earth style, and his extensive experience as a working mathematician. It accords with the field in focusing on whether mathematical entities are real. Franklin holds that recent discussion of this has oscillated between various forms of Platonism, and various forms of nominalism. He denies nominalism by holding that universals exist and denies Platonism by holding that they are concrete, not abstract - looking to Aristotle (...) for inspiration. (shrink)

A response is given here to Benacerraf's 1973 argument that mathematical platonism is incompatible with a naturalistic epistemology. Unlike almost all previous platonist responses to Benacerraf, the response given here is positive rather than negative; that is, rather than trying to find a problem with Benacerraf's argument, I accept his challenge and meet it head on by constructing an epistemology of abstract (i.e., aspatial and atemporal) mathematical objects. Thus, I show that spatio-temporal creatures like ourselves can attain knowledge about mathematical (...) objects by simply explaininghow they can do this. My argument is based upon the adoption of a particular version of platonism — full-blooded platonism — which asserts that any mathematical object which possiblycould exist actuallydoes exist. (shrink)

This book does three main things. First, it defends mathematical platonism against the main objections to that view (most notably, the epistemological objection and the multiple-reductions objection). Second, it defends anti-platonism (in particular, fictionalism) against the main objections to that view (most notably, the Quine-Putnam indispensability objection and the objection from objectivity). Third, it argues that there is no fact of the matter whether abstract mathematical objects exist and, hence, no fact of the matter whether platonism or anti-platonism is true.

In his Realism, Mathematics, and Modality, Hartry Field attempted to revitalize the epistemological case against mathematical platontism by challenging mathematical platonists to explain how we could be epistemically reliable with regard to the abstract objects of mathematics. Field suggested that the seeming impossibility of providing such an explanation tends to undermine belief in the existence of abstract mathematical objects regardless of whatever reason we have for believing in their existence. After more than two decades, Field’s explanatory challenge remains among the (...) best available motivations for mathematical nominalism. This paper argues that Field’s explanatory challenge misidentifies the central epistemological problem facing mathematical platonism. Contrary to Field’s suggestion, inexplicability of epistemic reliability does not act as an epistemic defeater. The failure to explain our epistemic reliability with respect to the existence and properties of abstract mathematical objects is simply one aspect of a broader failure to establish that we are epistemically reliable with respect to abstract mathematical objects in the first place. Ultimately, it is this broader failure that is the source of mathematical platonism’s real epistemological problems. (shrink)

Many mathematicians are platonists: they believe that the axioms of mathematics are true because they express the structure of a nonspatiotemporal, mind independent, realm. But platonism is plagued by a philosophical worry: it is unclear how we could have knowledge of an abstract, realm, unclear how nonspatiotemporal objects could causally affect our spatiotemporal cognitive faculties. Here I aim to make room in our metaphysical picture of the world for the causal relevance of abstracta.

Platonism in the philosophy of mathematics is the doctrine that there are mathematical objects such as numbers. John Burgess and Gideon Rosen have argued that that there is no good epistemological argument against platonism. They propose a dilemma, claiming that epistemological arguments against platonism either rely on a dubious epistemology, or resemble a dubious sceptical argument concerning perceptual knowledge. Against Burgess and Rosen, I show that an epistemological anti- platonist argument proposed by Hartry Field avoids both horns of their dilemma.

The best known and most widely discussed aspect of Kurt Gödel's philosophy of mathematics is undoubtedly his robust realism or platonism about mathematical objects and mathematical knowledge. This has scandalized many philosophers but probably has done so less in recent years than earlier. Bertrand Russell's report in his autobiography of one or more encounters with Gödel is well known:Gödel turned out to be an unadulterated Platonist, and apparently believed that an eternal “not” was laid up in heaven, where virtuous logicians (...) might hope to meet it hereafter.On this Gödel commented:Concerning my “unadulterated” Platonism, it is no more unadulterated than Russell's own in 1921 when in the Introduction to Mathematical Philosophy … he said, “Logic is concerned with the real world just as truly as zoology, though with its more abstract and general features.” At that time evidently Russell had met the “not” even in this world, but later on under the infuence of Wittgenstein he chose to overlook it.One of the tasks I shall undertake here is to say something about what Gödel's platonism is and why he held it.A feature of Gödel's view is the manner in which he connects it with a strong conception of mathematical intuition, strong in the sense that it appears to be a basic epistemological factor in knowledge of highly abstract mathematics, in particular higher set theory. Other defenders of intuition in the foundations of mathematics, such as Brouwer and the traditional intuitionists, have a much more modest conception of what mathematical intuition will accomplish. (shrink)

SummaryThe platonist, in affirming the principle of bivalence for sentences for which there is no decision procedure, disconnects their truth‐conditions from conditions that would enable us to prove them ‐ as if Goldbach's conjecture, say, might just happen to be true. According to Dummett, what has gone wrong here is that the meaning of the relevant sentences has been conceived so as to go beyond what could be learned in learning to use them, or displayed in using them competently. Dummett (...) draws the general conclusion that accounts of meaning must traffic only in decidable circumstances. I suggest that Dummett can be right about platonism but wrong in this general conclusion: the centrality of decidable circumstances in competent use of language is a special feature of mathematical language. This means that someone who recoils from the anti‐realism constituted by Dummett's generalized anti‐platonism, in the case of, say, statements about other minds, need not be recoiling into a close analogue of platonism, as Dummett suggests. We can reinstate the intuitive idea that platonism goes wrong by inappropriately modelling the epistemology and metaphysics of mathematics on the epistemology and metaphysics of the natural world. And we make room for the suggestion that anti‐realism makes a converse mistake; in this vein, I propose a picture of Dummettian anti‐realism as a novel expression of familiar and suspect epistemological and metaphysical thoughts. (shrink)

This paper concerns an epistemological objection against mathematical platonism, due to Hartry Field.The argument poses an explanatory challenge – the challenge to explain the reliability of our mathematical beliefs – which the platonist, it’s argued, cannot meet. Is the objection compelling? Philosophers disagree, but they also disagree on (and are sometimes very unclear about) how the objection should be understood. Here I distinguish some options, and highlight some gaps that need to be filled in on the potentially most compelling version (...) of the argument. (shrink)

Plato’s philosophy is important to Badiou for a number of reasons, chief among which is that Badiou considered Plato to have recognised that mathematics provides the only sound or adequate basis for ontology. The mathematical basis of ontology is central to Badiou’s philosophy, and his engagement with Plato is instrumental in determining how he positions his philosophy in relation to those approaches to the philosophy of mathematics that endorse an orthodox Platonic realism, i.e. the independent existence of a realm of (...) mathematical objects. The Platonism that Badiou makes claim to bears little resemblance to this orthodoxy. Like Plato, Badiou insists on the primacy of the eternal and immu- table abstraction of the mathematico-ontological Idea; however, Badiou’s reconstructed Platonism champions the mathematics of post-Cantorian set theory, which itself af rms the irreducible multiplicity of being. Badiou in this way recon gures the Platonic notion of the relation between the one and the multiple in terms of the multiple-without-one as represented in the axiom of the void or empty set. Rather than engage with the Plato that is gured in the ontological realism of the orthodox Platonic approach to the philosophy of mathematics, Badiou is intent on characterising the Plato that responds to the demands of a post-Cantorian set theory, and he considers Plato’s philosophy to provide a response to such a challenge. In effect, Badiou reorients mathematical Platonism from an epistemological to an ontological problematic, a move that relies on the plausibility of rejecting the empiricist ontology underlying orthodox mathematical Platonism. To draw a connec- tion between these two approaches to Platonism and to determine what sets them radically apart, this paper focuses on the use that they each make of model theory to further their respective arguments. (shrink)

According to Hartry Field, the mathematical Platonist is hostage of a dilemma. Faced with the request of explaining the mathematicians’ reliability, one option could be to maintain that the mathematicians are reliably responsive to a realm populated with mathematical entities; alternatively, one might try to contend that the mathematical realm conceptually depends on, and for this reason is reliably reflected by, the mathematicians’ (best) opinions; however, both alternatives are actually unavailable to the Platonist: the first one because it is in (...) tension with the idea that mathematical entities are causally ineffective, the second one because it is in tension with the suggestion that mathematical entities are mind-independent. John Divers and Alexander Miller have tried to reject the conclusion of this argument—according to which Platonism is inconsistent with a satisfactory epistemology for arithmetic—by redescribing the second horn of the dilemma in light of Crispin Wright’s notion of judgment-dependent truth; in particular they have contended that once arithmetical truth is conceived in this way the Platonist can have a substantial epistemology which does not conflict with the idea that the mathematical entities exist mind-independently. In this paper I analyze Wright’s notion of judgment-dependent truth, and reject Divers and Miller’s argument for the conclusion that arithmetical truth can be so characterized. In the final part, I address the worry that my argument generalizes very quickly to the conclusion that no area of discourse could be characterized as judgment-dependent. As against this conclusion, I indicate under what conditions—notably not satisfied in Divers and Miller’s case, but possibly satisfied in others—a discourse’s judgment-dependency can be successfully vindicated. (shrink)

In this paper, I challenge those interpretations of Frege that reinforce the view that his talk of grasping thoughts about abstract objects is consistent with Russell's notion of acquaintance with universals and with Gödel's contention that we possess a faculty of mathematical perception capable of perceiving the objects of set theory. Here I argue the case that Frege is not an epistemological Platonist in the sense in which Gödel is one. The contention advanced is that Gödel bases his Platonism on (...) a literal comparison between mathematical intuition and physical perception. He concludes that since we accept sense perception as a source of empirical knowledge, then we similarly should posit a faculty of mathematical intuition to serve as the source of mathematical knowledge. Unlike Gödel, Frege does not posit a faculty of mathematical intuition. Frege talks instead about grasping thoughts about abstract objects. However, despite his hostility to metaphor, he uses the notion of ‘grasping’ as a strategic metaphor to model his notion of thinking, i.e., to underscore that it is only by logically manipulating the cognitive content of mathematical propositions that we can obtain mathematical knowledge. Thus, he construes ‘grasping’ more as theoretical activity than as a kind of inner mental ‘seeing’. (shrink)

The present dissertation includes three chapters: chapter one 'Challenges to platonism'; chapter two 'counterparts of non-mathematical statements'; chapter three 'Nominalizing platonistic accounts of the predictive success of mathematics'. The purpose of the dissertation is to articulate a fundamental problem in the philosophy of mathematics and explore certain solutions to this problem. The central problematic is that platonistic mathematics is involved in the explanation and prediction of physical phenomena and hence its role in such explanations gives us good reason to believe (...) that platonism is true. On the other hand, we have grounds, essentially epistemological, for avoiding the use of platonistic mathematics. ;This philosophical tension can be relieved only by showing that good non-platonistic explanations of physical phenomena are available or by showing that the epistemological objections to platonism may be overcome. While both options are discussed in some detail, a certain emphasis is placed on the task of fashioning non-platonistic accounts of physical phenomena to replace the usual platonistic accounts. As is suggested in chapter one, the reason for this emphasis is that the referential and more broadly epistemological objections to platonism seem quite convincing. Of paramount interest in regards to an inquiry into the utility of mathematics is the status of biconditional statements connecting non-mathematical statements with their mathematical counterparts. ;In chapters two and three of the dissertation I address certain key philosophical issues surrounding the status of these biconditionals. The upshot of these chapters is that these biconditionals can be used to illuminate the utility of mathematics; and there is good reason to think an account of the utility of mathematics can be given without acknowledging the truth of mathematics. (shrink)

Field’s challenge to platonists is the challenge to explain the reliable match between mathematical truth and belief. The challenge grounds an objection claiming that platonists cannot provide such an explanation. This objection is often taken to be both neutral with respect to controversial epistemological assumptions, and a comparatively forceful objection against platonists. I argue that these two characteristics are in tension: no construal of the objection in the current literature realises both, and there are strong reasons to think that no (...) version of Field’s epistemological objection which has both Neutrality and Force can be construed. (shrink)

Mathematics as a Science of Patterns is the definitive exposition of a system of ideas about the nature of mathematics which Michael Resnik has been elaborating for a number of years. In calling mathematics a science he implies that it has a factual subject-matter and that mathematical knowledge is on a par with other scientific knowledge; in calling it a science of patterns he expresses his commitment to a structuralist philosophy of mathematics. He links this to a defence of realism (...) about the metaphysics of mathematics--the view that mathematics is about things that really exist. Resnik's distinctive philosophy of mathematics is here presented in an accessible and systematic form: it will be of value not only to specialists in this area, but to philosophers, mathematicians, and logicians interested in the relationship between these three disciplines, or in truth, realism, and epistemology. (shrink)

Hartry Field's formulation of an epistemological argument against platonism is only valid if knowledge is constrained by a causal clause. Contrary to recent claims (e.g. in Liggins (2006), Liggins (2010)), Field's argument therefore fails the very same criterion usually taken to discredit Benacerraf's earlier version.

This paper aims to provide hyperintensional foundations for mathematical platonism. I examine Hale and Wright's (2009) objections to the merits and need, in the defense of mathematical platonism and its epistemology, of the thesis of Necessitism. In response to Hale and Wright's objections to the role of epistemic and metaphysical modalities in providing justification for both the truth of abstraction principles and the success of mathematical predicate reference, I examine the Necessitist commitments of the abundant conception of properties endorsed by (...) Hale and Wright and examined in Hale (2013), and demonstrate how a two-dimensional approach to the epistemology of mathematics is consistent with Hale and Wright's notion of there being non-evidential epistemic entitlement rationally to trust that abstraction principles are true. A choice point that I flag is that between availing of intensional or hyperintensional semantics. The hyperintensional semantic approach that I advance is a topic-sensitive epistemic two-dimensional truthmaker semantics. I countenance a hyperintensional semantics for novel epistemic abstractionist modalities. I suggest that observational type theory can be applied to first-order abstraction principles in order to make abstraction principles recursively enumerable. Epistemic and metaphysical states and possibilities may thus be shown to play a constitutive role in vindicating the reality of mathematical objects and truth, and in providing a conceivability-based route to the truth of abstraction principles as well as other axioms and propositions in mathematics. (shrink)

This paper draws together two strands in the debate over the existence of mathematical objects. The first strand concerns the notion of extra-mathematical explanation: the explanation of physical facts, in part, by facts about mathematical objects. The second strand concerns the access problem for platonism: the problem of how to account for knowledge of mathematical objects. I argue for the following conditional: if there are extra-mathematical explanations, then the core thesis of the access problem is false. This has implications for (...) nominalists and platonists alike. Platonists can make a case for epistemic access to mathematical objects by providing evidence in favour of the existence of extra-mathematical explanations. Nominalists, by contrast, can use the access problem to cast doubt on the idea that mathematical objects play a substantive role in scientific explanation. (shrink)

In the introduction to his Realism, mathematics and modality, and in earlier papers included in that collection, Hartry Field offered an epistemological challenge to platonism in the philosophy of mathematics. Justin Clarke-Doane Truth, objects, infinity: New perspectives on the philosophy of Paul Benacerraf, 2016) argues that Field’s challenge is an illusion: it does not pose a genuine problem for platonism. My aim is to show that Clarke-Doane’s argument relies on a misunderstanding of Field’s challenge.

This volume gathers an international team of renowned scholars in the fields of ancient greek philosophy, in order to explore the continuous but changing dialogue between Platonism and Aristotelianism from the early imperial age to the end of Antiquity. While most chapters concern Platonists (Philo, Plutarch, Plotinus, Syrianus, Proclus, Damascius, Philoponus), and their uses or criticism of Aristotle's doctrines, several chapters are also devoted to Peripatetic authors (Boethius and mostly Alexander of Aphrodisias) and their attitudes towards Plato's positions. Each of (...) the eleven chapters draws the attention to specific polemical contexts and philosophical problems which made Platonists and Aristotelians unite against common adversaries like the Stoics, or split up, not only in the fields of metaphysics and cosmology, but also in epistemology, psychology and ethics. (shrink)

Mathematics plays a central role in much of contemporary science, but philosophers have struggled to understand what this role is or how significant it might be for mathematics and science. In this book Christopher Pincock tackles this perennial question in a new way by asking how mathematics contributes to the success of our best scientific representations. In the first part of the book this question is posed and sharpened using a proposal for how we can determine the content of a (...) scientific representation. Several different sorts of contributions from mathematics are then articulated. Pincock argues that each contribution can be understood as broadly epistemic, so that what mathematics ultimately contributes to science is best connected with our scientific knowledge. In the second part of the book, Pincock critically evaluates alternative approaches to the role of mathematics in science. These include the potential benefits for scientific discovery and scientific explanation. A major focus of this part of the book is the indispensability argument for mathematical platonism. Using the results of part one, Pincock argues that this argument can at best support a weak form of realism about the truth-value of the statements of mathematics. The book concludes with a chapter on pure mathematics and the remaining options for making sense of its interpretation and epistemology. Thoroughly grounded in case studies drawn from scientific practice, this book aims to bring together current debates in both the philosophy of mathematics and the philosophy of science and to demonstrate the philosophical importance of applications of mathematics. (shrink)

It is widely assumed that platonism with respect to a discourse of metaphysical interest, such as fictional or mathematical discourse, affords a better account of the semantic appearances than nominalism, other things being equal. Of course, other things may not be equal. For example, platonism is supposed to come at the cost of a plausible epistemology and ontology. But the hedged claim is often treated as a background assumption. It is motivated by the intuitively stronger one that the platonist can (...) take the semantic appearances at ‘face-value’ while the nominalist must resort to ad hoc and technically problematic machinery in order to explain those appearances away. In this article, I argue that, on any natural construal of ‘face-value’, the platonist, like the nominalist, is not able to take the semantic appearances at face-value. And insofar as the nominalist is forced to resort to ad hoc and technically awkward devices in order to explain those appearances away, the platonist must resort to such devices as well. One moral of the story is that the thesis that platonism affords a better account of the semantic appearances than nominalism – even other things being equal – is not trivial. Another is that we should rethink a widespread methodology in metaphysics. (shrink)

There is a wide range of realist but non-Platonist philosophies of mathematics—naturalist or Aristotelian realisms. Held by Aristotle and Mill, they played little part in twentieth century philosophy of mathematics but have been revived recently. They assimilate mathematics to the rest of science. They hold that mathematics is the science of X, where X is some observable feature of the (physical or other non-abstract) world. Choices for X include quantity, structure, pattern, complexity, relations. The article lays out and compares these (...) options, including their accounts of what X is, the examples supporting each theory, and the reasons for identifying the science of X with (most or all of) mathematics. Some comparison of the options is undertaken, but the main aim is to display the spectrum of viable alternatives to Platonism and nominalism. It is explained how these views answer Frege’s widely accepted argument that arithmetic cannot be about real features of the physical world, and arguments that such mathematical objects as large infinities and perfect geometrical figures cannot be physically realized. (shrink)

My thesis discusses the unique challenge that platonistic mathematics poses to philosophical naturalism. It has two main parts. ;The first part discusses the three most important approaches to my problem found in the literature: First, W. V. Quine's holistic empiricist defense of mathematical platonism; then, the nominalists' argument that mathematical platonism is naturalistically unacceptable; and finally, a radical form of naturalism, due to John Burgess and Penelope Maddy, which dismisses any philosophical criticism of a successful science such as mathematics. I (...) find faults with all of these approaches. ;The second part attempts to do better. First, I develop an improved epistemological challenge to mathematical platonism. Roughly, this challenge asks for an account of what mathematicians' justification for believing in platonistic mathematics consists in. I argue this challenge is immune to the criticism I leveled against the traditional challenges. To show that it has bite, I apply this challenge to Quine's philosophy of mathematics. I argue this shows that Quine must invoke, in addition to his confirmational holism, a semantic indeterminacy thesis that is so radical as to be implausible. Finally, I attempt to develop a better response to the improved challenge. I defend an unorthodox view of the concept of an object and argue this makes room for a neo-Dedekindian view of mathematical objects which identifies mathematical existence with the logical coherence of the theory describing the structure in question. This view transforms metaphysical and epistemological questions about mathematical objects into corresponding, but more tractable questions about the logical notion of coherence. (shrink)

We informally discuss some recent results on the incompleteness of formal systems. These theorems, which are of great importance to contemporary mathematical epistemology, are proved using a variety of conceptual tools provably stronger than those of finitary axiomatisations. Those tools require no mathematical ontology, but rather constitute particularly concrete human constructions and acts of comprehending infinity and space rooted in different forms of knowledge. We shall also discuss, albeit very briefly, the mathematical intelligence both of God and of computers. We (...) hope in this manner to help the reader overcome formalist reductionism, while avoiding naive Platonist ontologies, typical symptoms of Godelitis which affected many in the last seventy years. (shrink)

Minimalism and Trivialism are two recent forms of lightweight Platonism in the philosophy of mathematics: Minimalism is the view that mathematical objects arethinin the sense that “very little is required for their existence”, whereas Trivialism is the view that mathematical statements have trivial truth‐conditions, that is, that “nothing is required of the world in order for those conditions to be satisfied”. In order to clarify the relation between the mathematical and the non‐mathematical domain that these views envisage, it has recently (...) been proposed that both Linnebo's notion of sufficiency and Rayo's “just is”‐operator can, or even should, be interpreted in terms of metaphysicalgrounding. This interpretation makes Minimalism and Trivialism akin to Aristotelianism in the philosophy of mathematics, according to which mathematical entities depend for their existence and their properties on non‐mathematical ones. In this paper we raise a general objection to this interpretation. We highlight a tension – a “Big Picture” Problem – between the metaphysical picture underlying both Minimalism and Trivialism, on the one side, and the metaphysics of Platonism and Aristotelianism on the other. We then consider various ways in which Linnebo and Rayo could respond. We finally argue that Minimalism and Trivialism are closer to Aristotelianism than to Platonism; however, even though these positions are not forms of traditional Platonism, they are not standard forms of Aristotelianism either. (shrink)

In this paper we examine Lewis's attempts to provide an epistemology of modality and we argue that he fails to provide an account that properly weds his metaphysics with an epistemology that explains the knowledge of modality that both he and his critics grant. We argue that neither the appeals to acceptable paraphrases of ordinary modal discourse nor parallels with Platonistic theories of mathematics suffice. We conclude that no proper epistemology for modal realism has been provided and that one is (...) needed. (shrink)

Several philosophers have suggested that some scientific explanations work not by virtue of describing aspects of the world’s causal history and relations, but rather by citing mathematical facts. This paper investigates what mathematical facts could be in order for them to figure in such “distinctively mathematical” scientific explanations. For “distinctively mathematical explanations” to be explanations by constraint, mathematical language cannot operate in science as representationalism or platonism describes. It can operate as Aristotelian realism describes. That is because Aristotelian realism enables (...) mathematics to apply to the physical world without a morphism’s mediation. (shrink)

Recent years have seen a number of naturalist accounts of mathematics. Philip Kitcher’s version is one of the most important and influential. This paper includes a critical exposition of Kitcher’s views and a discussion of several issues including: mathematical epistemology, practice, history, the nature of applied mathematics. It argues that naturalism is an inadequate account and compares it with mathematical Platonism, to the advantage of the latter.

According to Quine’s indispensability argument, we ought to believe in just those mathematical entities that we quantify over in our best scientific theories. Quine’s criterion of ontological commitment is part of the standard indispensability argument. However, we suggest that a new indispensability argument can be run using Armstrong’s criterion of ontological commitment rather than Quine’s. According to Armstrong’s criterion, ‘to be is to be a truthmaker (or part of one)’. We supplement this criterion with our own brand of metaphysics, 'Aristotelian (...) (...) realism', in order to identify the truthmakers of mathematics. We consider in particular as a case study the indispensability to physics of real analysis (the theory of the real numbers). We conclude that it is possible to run an indispensability argument without Quinean baggage. (shrink)

Platonists and nominalists disagree about whether mathematical objects exist. But they almost uniformly agree about one thing: whatever the status of the existence of mathematical objects, that status is modally necessary. Two notable dissenters from this orthodoxy are Hartry Field, who defends contingent nominalism, and Mark Colyvan, who defends contingent Platonism. The source of their dissent is their view that the indispensability argument provides our justification for believing in the existence, or not, of mathematical objects. This paper considers whether commitment (...) to the indispensability argument gives one grounds to be a contingentist about mathematical objects. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:After Gödel: Platonism and Rationalism in Mathematics and LogicMark C. R. SmithRichard Tieszen. After Gödel: Platonism and Rationalism in Mathematics and Logic. Oxford-New York: Oxford University Press, 2011. Pp. xi + 245. Cloth, $75.00.Tieszen’s new book offers a synthesis and extension of his longstanding project of bringing the method of Husserl’s phenomenology to bear on fundamental questions—both epistemological and ontological—in the philosophy of mathematics. Gödel held Husserl’s philosophy (...) in high regard, and thought that it offered the most promising avenue for an adequate understanding of the foundations of mathematical thought and practice, but Gödel himself did not give a full systematic statement of how phenomenology might carry out that project. Tieszen takes up the task in this book, which is structured around two main guiding themes. The first is to locate the sources of Gödel’s philosophical views—principally [End Page 303] in Plato, Leibniz, and of course Husserl, along with Kant as a sort of backcloth—and the second is to argue that from these materials, a promising rationalism in mathematics and logic can be consistently articulated. Along the way we also encounter a good many of Gödel’s arguments against an array of reductive positions, Hilbert’s formalism and Carnap’s “logical syntax” project among them, as well as arguments against the prospects of a mechanical or purely computational understanding of the human mind. Many of the arguments (both negative and positive) stem from a reflection on the consequences of Gödel’s landmark incompleteness results of 1931.The core of Tieszen’s positive proposals comes in chapters 4, 5, and 6: here is where we meet with “constituted Platonism,” Tieszen’s name for the rationalist, realist synthesis of Husserl’s method and Gödel’s mathematical insights. Methodologically, the starting point is the actual practice of mathematics as a human undertaking, and its conditions of possibility. At the most general level, it is characteristic of thought to be intentional, that is, to be (or try to be) about something, to have a target, to be a bearer of meaning. So it goes for thought about items in sensory awareness, about fictional objects, or about mathematical subject-matter. Concerning the latter, what we encounter in mathematical experience are frequently “phenomena that resist our will, so that we are ‘forced’ in certain directions” (170); what accounts for this resistance to our will are invariants, which have the further characteristics of repeatability—both for a single subject, and among many subjects—and availability for convergence (221), which, I take it, means availability as structures or concepts upon which many independent rational investigators will come to rest. Thinking mathematical thoughts is quite unlike thinking thoughts about fictional items, because fictions are indefinitely plastic in the face of human will. It is also unlike thought about sensory items, in that the intentional objects at issue are not available to outer sense; but from another angle it is more like thought about real material items than imaginary beings, because our mathematical thoughts are exposed to the possibility of error or misrepresentation in various ways. (An elementary example: most people think that 1 is distinct from 0.9999... repeating: this is a misrepresentation, because they are in fact identical.)The phenomenology of mathematical practice is such that we assay various conjectures and proposals about invariants already given to consciousness by previous practice, and discover what further invariant structures or concepts are revealed as necessary constraints upon the various possibilities that we can experimentally float for ourselves. Sometimes our conjectures or intentions are fulfilled, sometimes they are frustrated; but it is the very fact of fulfillment and frustration which points us to a Platonic reality. It is not the noumenal realm of the “naive” Platonist, in Tieszen’s phrase, but nevertheless an objective reality marked off “on the basis of what stabilizes or becomes invariant in our experience, on the basis of what has a history and a sedimentation that permits of further elaboration, development, constraints, surprises, and so on” (101). In something like this way, human reason and consciousness “constitute the meaning of being” of mathematical objects... (shrink)

It is argued here that mathematical objects cannot be simultaneously abstract and perceptible. Thus, naturalized versions of mathematical platonism, such as the one advocated by Penelope Maddy, are unintelligble. Thus, platonists cannot respond to Benacerrafian epistemological arguments against their view vias Maddy-style naturalization. Finally, it is also argued that naturalized platonists cannot respond to this situation by abandoning abstractness (that is, platonism); they must abandon perceptibility (that is, naturalism).

The present paper discusses a proposal which says,roughly and with several qualifications, that thecollection of mathematical truths is identical withthe set of theorems of ZFC. It is argued that thisproposal is not as easily dismissed as outright falseor philosophically incoherent as one might think. Some morals of this are drawn for the concept ofmathematical knowledge.

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:The Impact of Aristotelianism on Modern PhilosophyJean-Robert ArmogatheRiccardo Pozzo, editor. The Impact of Aristotelianism on Modern Philosophy. Washington, D.C.: The Catholic University of America Press, 2004. Pp. xvi + 336. Cloth, $69.95.The status of a "great" philosopher is to stand out for centuries, asking questions in such a way that the answers can never be definitive. Not so many of them are able to stand such a severe (...) proof. Aristotle phrased some questions we are still groping to answer. It was a very good idea to ask thirteen scholars to deliver a lecture series at the Catholic University of America during the Fall 1999 about the reception of Aristotle's theory of intellectual virtues (Nich. Ethics VI). The speakers did not stick to this issue, and enlarged their purpose to a general approach of Aristotle's receptions in various moments of Western modern philosophy.Edward Mahoney complements Charles Schmitt's basic introduction to Aristotle and the Renaissance, with some very valuable pages about Cardinal Bessarion's contribution to the Byzantine debate aroused in 1439 by Plethon's comparison between Plato and Aristotle (in favor of the former). Along with Charles Schmitt, Antonino Poppi is the best specialist of the Paduan tradition, and wrote a very qualified paper about Zabarella (1533-89), who shaped Aristotelianism into the rigorous science of the schoolbooks: for centuries, Aristotle is read through Zabarella's glasses. Apart from a bird's view on recent Galilean studies (where Alistair Crombie is not mentioned), William A. Wallace makes his point about Aristotle's influence on Galilean logics, linking Galileo's 1640 letter to Liceti (where he states that, in matters of logic, he has been an Aristotelian all his life) to the scientist's deep knowledge as revealed by the logical questions in one of the juvenile treatises (ms 27 in Florence, more thoroughly studied in Wallace's book, Galileo's Logic of Discovery and Proof [Dordrecht, 1992]). John Doyle, a specialist of Late Scholastic Philosophy, figures out a [End Page 209] strange character, the French Jesuit André Semery (1630-1717), who taught for thirty years at the Collegium romanum. In a very anti-Aristotelian way, he holds a definite belief in metaphysical beings of reason. The boundary between what we can think and say is quietly stepped over, when Semery and other Jesuits begin to think about thinking, opening a very modern path which leads to Brentano and Quine. Christia Mercer states that Leibniz's combination of a Platonist epistemology with an Aristotelian conception of nature brings a very innovative view in ethics. A very forceful paper by Richard L. Velkley compares Rousseau's politics to Aristotle's view of man (the paper became a chapter of his 2002 impressive book Being after Rousseau), while Riccardo Pozzo gives a short presentation of Aristotle's reception in modern Germany, and an elaborate analysis of Kant's debt to Aristotle for the intellectual virtues. Hegel's appropriation of Aristotelian intellect is presented by Alfredo Ferrarin, while Michael Davis reconstructs Nietzsche's path from Aristotle to the tragedy and back, in a very convincing way. Husserl (Richard Cobb-Stevens), Heidegger (Stanley Rosen), Wittgenstein (Daniel Dahlstrom) and Gadamer (Enrico Berti) conclude brilliantly the series, showing how the thought of the Stagirite fertilized contemporary philosophers, in a permanent dialogue of disagreement or borrowing, never at rest, and never leaving anyone indifferent. The old Greek man remains a vivid debater for our age of anxiety.Jean-Robert ArmogatheThe University of Paris-SorbonneCopyright © 2005 Journal of the History of Philosophy, Inc.... (shrink)

Chihara seeks to avoid commitment to mathematical objects by replacing traditional assertions of the existence of mathematical objects with assertions about possibilities of constructing certain open-sentence tokens. I argue that Chihara's project can be defended against several important objections, but that it is no less epistemologically problematic than its platonistic competitors.

The philosophy of mathematics of the later Wittgenstein is normally not taken very seriously. According to a popular objection, it cannot account for mathematical necessity. Other critics have dismissed Wittgenstein's approach on the grounds that his anti-platonism is unable to explain mathematical objectivity. This latter objection would be endorsed by somebody who agreed with Paul Benacerraf that any anti-platonistic view fails to describe mathematical truth. This paper focuses on the problem proposed by Benacerraf of reconciling the semantics with the epistemology (...) for mathematics. It is claimed that there is a way of solving Benacerrafs problem along the lines suggested by Wittgenstein's later remarks on mathematics. This will require demonstrating that a satisfactory conception of mathematical objectivity can be extracted from his mature philosophy. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:The Impact of Aristotelianism on Modern PhilosophyJean-Robert ArmogatheRiccardo Pozzo, editor. The Impact of Aristotelianism on Modern Philosophy. Washington, D.C.: The Catholic University of America Press, 2004. Pp. xvi + 336. Cloth, $69.95.The status of a "great" philosopher is to stand out for centuries, asking questions in such a way that the answers can never be definitive. Not so many of them are able to stand such a severe (...) proof. Aristotle phrased some questions we are still groping to answer. It was a very good idea to ask thirteen scholars to deliver a lecture series at the Catholic University of America during the Fall 1999 about the reception of Aristotle's theory of intellectual virtues (Nich. Ethics VI). The speakers did not stick to this issue, and enlarged their purpose to a general approach of Aristotle's receptions in various moments of Western modern philosophy.Edward Mahoney complements Charles Schmitt's basic introduction to Aristotle and the Renaissance, with some very valuable pages about Cardinal Bessarion's contribution to the Byzantine debate aroused in 1439 by Plethon's comparison between Plato and Aristotle (in favor of the former). Along with Charles Schmitt, Antonino Poppi is the best specialist of the Paduan tradition, and wrote a very qualified paper about Zabarella (1533-89), who shaped Aristotelianism into the rigorous science of the schoolbooks: for centuries, Aristotle is read through Zabarella's glasses. Apart from a bird's view on recent Galilean studies (where Alistair Crombie is not mentioned), William A. Wallace makes his point about Aristotle's influence on Galilean logics, linking Galileo's 1640 letter to Liceti (where he states that, in matters of logic, he has been an Aristotelian all his life) to the scientist's deep knowledge as revealed by the logical questions in one of the juvenile treatises (ms 27 in Florence, more thoroughly studied in Wallace's book, Galileo's Logic of Discovery and Proof [Dordrecht, 1992]). John Doyle, a specialist of Late Scholastic Philosophy, figures out a [End Page 209] strange character, the French Jesuit André Semery (1630-1717), who taught for thirty years at the Collegium romanum. In a very anti-Aristotelian way, he holds a definite belief in metaphysical beings of reason. The boundary between what we can think and say is quietly stepped over, when Semery and other Jesuits begin to think about thinking, opening a very modern path which leads to Brentano and Quine. Christia Mercer states that Leibniz's combination of a Platonist epistemology with an Aristotelian conception of nature brings a very innovative view in ethics. A very forceful paper by Richard L. Velkley compares Rousseau's politics to Aristotle's view of man (the paper became a chapter of his 2002 impressive book Being after Rousseau), while Riccardo Pozzo gives a short presentation of Aristotle's reception in modern Germany, and an elaborate analysis of Kant's debt to Aristotle for the intellectual virtues. Hegel's appropriation of Aristotelian intellect is presented by Alfredo Ferrarin, while Michael Davis reconstructs Nietzsche's path from Aristotle to the tragedy and back, in a very convincing way. Husserl (Richard Cobb-Stevens), Heidegger (Stanley Rosen), Wittgenstein (Daniel Dahlstrom) and Gadamer (Enrico Berti) conclude brilliantly the series, showing how the thought of the Stagirite fertilized contemporary philosophers, in a permanent dialogue of disagreement or borrowing, never at rest, and never leaving anyone indifferent. The old Greek man remains a vivid debater for our age of anxiety.Jean-Robert ArmogatheThe University of Paris-SorbonneCopyright © 2005 Journal of the History of Philosophy, Inc.... (shrink)