Minimalism is the view that our concept of truth is constituted by our disposition to accept instances of the truth schema ‘The proposition that p is true if and only if p’. The generalisation problem is the challenge to account for universal generalisations concerning logical truths such as ‘Every proposition of the form 〈if p, then p〉 is true’. This paper argues that such generalisations can be deduced using a single example of the logical truth in question and a single (...) corresponding instance of the truth schema, employing the logical method of reasoning with arbitrary instances of universal and existential generalisations. Suggesting an inferentialist construal of Minimalism, the paper introduces conditional and general acceptance dispositions, distinguishes inferential meaning constitution from implicit definition, highlights the inferential nature of acceptance of instances of the truth schema, sketches a suitable account of structured propositions, compares higher-order with first-order means of quantification, and argues that the conception of truth Minimalism attributes to ordinary speakers is essentially inferential. It finally applies the deductive strategy to generalisations concerning logical validity as well as more complex logical truths. (shrink)

The thesis that nothing is true has long been thought to be a self-refuting position not worthy of serious philosophical consideration. Recently, however, the thesis of alethic nihilism—that nothing is true—has been explicitly defended (notably by David Liggins). Nihilism is also, I argue, a consequence of other views about truth that have recently been advocated, such as fictionalism about truth and the inconsistency account. After offering an account of alethic nihilism, and how it purports to avoid the self-refutation problem, I (...) argue that it avoids the problem at the expense of changing the subject. I then present other arguments against nihilism and responses to the considerations offered in defense of it. The only tenable position is that something is indeed true. (shrink)

I offer an explicit account of the underdetermination thesis as well as of the many challenges it poses to scientific realism; a way to answer to these challenges is explored and outlined, by shifting attention to the content of theories. I argue that, even if we have solid grounds (as I contend we do) to support that some varieties of the underdetermination thesis are true, scientific realism can still offer an adequate picture of the aims and achievements of science.

It is commonplace to describe the pragmatist conception of truth as incompatible with correspondence theory. This popular description relies on a deflationary reading of Peirce and James’s many apparent endorsements of correspondence. This reading says they regarded it as a mere platitude or truism, not as a substantive piece of philosophical theorizing. There are two main reasons typically offered in support of this platitude narrative – its consonance with Peirce’s original formulation of PT from 1878, and the objections that pragmatists (...) frequently raised against various notions traditionally associated with CT. I argue that neither reason is compelling and that PT and CT are compatible conceptions of truth. (shrink)

What is the source of logical and mathematical truth? This book revitalizes conventionalism as an answer to this question. Conventionalism takes logical and mathematical truth to have their source in linguistic conventions. This was an extremely popular view in the early 20th century, but it was never worked out in detail and is now almost universally rejected in mainstream philosophical circles. Shadows of Syntax is the first book-length treatment and defense of a combined conventionalist theory of logic and mathematics. It (...) argues that our conventions, in the form of syntactic rules of language use, are perfectly suited to explain the truth, necessity, and a priority of logical and mathematical claims, as well as our logical and mathematical knowledge. (shrink)

The concept of truth and competing philosophical theories on what truth amounts to have an important place in contemporary philosophy. The aim of this chapter is to give a synopsis of different theories of truth and the particular philosophical issues related to the concept of truth. The literature on this topic is vast, and we must necessarily be rather selective and very brief about complex questions of interpretation of various philosophers. The focus of the chapter is mainly on selected systematic (...) issues and the most influential and well-established philosophical theories and key concepts. (shrink)

Truth is a fundamental philosophical concept that, despite its common and everyday use, has resisted common-sense formulations. At this point, one may legitimately wonder if there even is a common-sense notion of truth or what it could look like. In response, I propose here a common-sense account of truth based on four “truisms” that set a baseline for how to go about building an account of truth. Drawing on both ordinary language philosophy and contemporary pragmatic approaches to truth, I defend (...) a pragmatic, common-sense theory of truth. The result is a theory that focuses the use and function of truth while also emphasizing its “subject-independence.”. (shrink)

Hartry Field distinguished two concepts of type‐free truth: scientific truth and disquotational truth. We argue that scientific type‐free truth cannot do justificatory work in the foundations of mathematics. We also present an argument, based on Crispin Wright's theory of cognitive projects and entitlement, that disquotational truth can do justificatory work in the foundations of mathematics. The price to pay for this is that the concept of disquotational truth requires non‐classical logical treatment.

The article is an extended critical discussion of Kevin Scharp’s Replacing Truth. Scharp’s case for the claim that the concept of truth is inconsistent is criticized, and so is his case for the claim that the concept of truth must be replaced because of its inconsistency.

Making a connection between ‘post-modernism’ and post-truth has by now become a standard trope, both within academia and popular discourse, despite post-truth’s only recent emergence as a concept. Such claims are often rather vague and fanciful and lack an altogether credible account of either phenomenon in many cases. This Chapter argues however that within a legal context, there is the emergence of a legal post-truth which is the direct consequence of a concrete form of post-modernity within legal practice and thought. (...) While law may be called upon to engage in judgments of ‘truth’ in numerous interesting ways, it does not itself have any particular form of privileged access to the truth of statements or allegations, even though it is often treated as doing so. However, the most persistent question which law must deal with, and indeed the most persistent question within legal philosophy, relates to a deeper form of inquiry into truth: the question of legal truth. In simple terms this refers to the correctness of any particular proposition of law. Within legal theory, this expands to the larger question of what makes, in general, any legal proposition valid, or true. Reflecting upon legal scholarship through the lens of truth reveals that theories of law can be broken down into two broad and radically distinct categories. On the one hand, there exist empirical accounts of law which fundamentally understand questions of legal truth as social questions whose answers are empirically demonstrable. On the other hand, there are ‘idealist’ accounts of law which view legal content, and hence truth, as existing in some way or other in a manner which transcends social practice and which is autonomous from it. Both of these classical accounts, while radically different, share an interesting paradox: they see truth in law as an objective fact, but one which is fleeting and distant, far from the paradigm of legal certainty upon which the ideology of law is partly based. However, such accounts of legal truth share many other unstated aspects, and are largely based upon ideas which place the separateness and completeness of legal systems at their heart, providing either a unified ideal or a unified empirically observable social practice. However, they are share a common flaw, namely the failure to account for what might be called a post-modern phase of development in law, in which ordinary legal questions now regularly require the complex and non-hierarchical interaction of competing legal systems with different ‘truths’ and different ways of arriving at such truths. Such phenomena are commonly referred to as legal or, at times, constitutional ‘pluralism’. This post-modern turn within law has also produced therefore what we might call a form of post-truth within law. This is particularly significant because it places under great strain both the empirical and ideal accounts of legal truth and require us to re-elaborate an account of what makes a legal proposition true. From certain perspectives, this legal post-truth shares certain important aspects with the cultural phenomenon of post-truth, namely its apparently capricious and deracinated nature. However, it is argued in this Chapter that, in the legal context at least, post-truth allows for the transcendence of the empirical/ideal divide and the revealing of deeper forms of legal truth and our ability to account for them through theory or, put more simply, explanation. Upon greater reflection, legal truth is generated by the very forms of argument, or modes, which allow access to it. Such forms of argument exist also to produce legal truths outside and between legal orders where these appear to conflict or collide. While some legal scholars and others claim that such pressures on structures of knowledge reveal the end of the potential for law to generate truth, it is argued here that, on the contrary, they require a more open and more transparent use of the pure methods and modes of reason which both reveal but also generate legal truth in the first place. This is relevant to post-truth more generally in one specific way, despite the numerous idiosyncrasies of legal truth and knowledge: when assertions of truth within structures of power seem to come to embody the perspectivism and relativism used as methods of deconstruction, the post-modern and deconstructionist projects themselves require radical change: they stay true to their goal of deconstructing structures and discourses of power by applying the classical epistemologies which are rejected by those in power. Just as legal outcomes which are asserted rather than reasoned or justified are most convincingly deconstructed through sober legal modes, so can the post-modernist project find purpose in a world where dominant epistemes seem to have come to embody a simplistic version of post-modernist critiques. (shrink)

What is deflationism about truth? There are many questions that can be raised about this, given the numerous different characterizations of deflationism in the literature. Here I attend to questions about the characterization of deflationism that arise when we carefully distinguish between issues pertaining to concepts and issues pertaining to properties.

Conferring legal personhood on purely synthetic entities is a very real legal possibility, one under consideration presently by the European Union. We show here that such legislative action would be morally unnecessary and legally troublesome. While AI legal personhood may have some emotional or economic appeal, so do many superficially desirable hazards against which the law protects us. We review the utility and history of legal fictions of personhood, discussing salient precedents where such fictions resulted in abuse or incoherence. We (...) conclude that difficulties in holding “electronic persons” accountable when they violate the rights of others outweigh the highly precarious moral interests that AI legal personhood might protect. (shrink)

In this paper, we offer a brief, critical survey of contemporary work on truth. We begin by reflecting on the distinction between substantivist and deflationary truth theories. We then turn to three new kinds of truth theory—Kevin Scharp's replacement theory, John MacFarlane's relativism, and the alethic pluralism pioneered by Michael Lynch and Crispin Wright. We argue that despite their considerable differences, these theories exhibit a common "pluralizing tendency" with respect to truth. In the final section, we look at the underinvestigated (...) interface between metaphysical and formal truth theories, pointing to several promising questions that arise here. (shrink)

Widespread deflationistic readings of Quine misrepresent his view of disquotation’s significance and the truth predicate’s utility. I demonstrate this by answering a question that philosophers have not directly addressed: how does Quine understand the philosophical problem of truth? A primary thesis of this paper is that we can answer this question only by working from within Quine’s naturalistic framework. Drawing on neglected texts from Quine's corpus, I defend the view that, for Quine, the problem of truth emerges from the development (...) of science, in particular, from logical theorizing. I show that disquotation itself, from this Quinean point of view, is the problematic phenomenon calling for philosophical reflection. I conclude by arguing that Quine does not envisage the kind of explanatory role for disquotation taken up by contemporary deflationists, and he shows no interest in the task that animates deflationism, namely, to show that concerns with truth’s nature are fundamentally confused. (shrink)

In this entry I will offer a survey of the contemporary debate on fic- tionalism, which is a distinctive anti-realist view about certain regions of discourse that are valued for their usefulness rather than their truth.

Can one combine Davidsonian semantics with a deflationary conception of truth? Williams argues, contra a common worry, that Davidsonian semantics does not require truth-talk to play an explanatory role. Horisk replies that, in any event, the expressive role of truth-talk that Williams emphasizes disqualifies deflationary accounts—at least extant varieties—from combination with Davidsonian semantics. She argues, in particular, that this is so for Quine's disquotationalism, Horwich's minimalism, and Brandom's prosententialism. I argue that Horisk fails to establish her claim in all three (...) cases. This involves clarifying Quine’s understanding of a purely referential occurrence; explaining how Davidsonians can avail themselves of a syntactic treatment of lexical ambiguity; and correcting a common misreading of Brandom (answering along the way an objection offered by Künne as well). (shrink)

In the last decades two different and apparently unrelated lines of research have increasingly connected mathematics and evolutionism. Indeed, on the one hand different attempts to formalize darwinism have been made, while, on the other hand, different attempts to naturalize logic and mathematics have been put forward. Those researches may appear either to be completely distinct or at least in some way convergent. They may in fact both be seen as supporting a naturalistic stance. Evolutionism is indeed crucial for a (...) naturalistic perspective, and formalizing it seems to be a way to strengthen its scientificity. The paper shows that, on the contrary, those directions of research may be seen as conflicting, since the conception of knowledge on which they rest may be undermined by the consequences of accepting an evolutionary perspective. (shrink)

Our aim in this paper is to replace the old concept of truth in mathematics, based on the Set Structure provided with idea of true and false characterized by the presence of a characteric function \, by a mathematical structures founded on the idea of Topos, the triple structure \\}\) and the notion of Gradual Truth or Steps from the truth. Our motivations is to understand the mathematical structures underlying the emergence’s mechanism and phenomena. We think that this approach could (...) be useful to better appreciate the subtleties of the notion of truth and gives us a better understanding of the complex and changing phenomena. (shrink)

This essay argues that deflationism is incompatible with the phenomenon of referential indeterminacy. This puts the deflationist in the difficult position of having to deny the possibility of what otherwise seems like a manifest and theoretically important phenomenon. Section 1 provides background on deflationism. Section 2 considers an intuitive argument by Stephen Leeds to the effect that deflationism precludes RI; the essay argues that this argument does not succeed. The rest of the essay presents its own, distinct argument for the (...) incompatibility of deflationism and RI. Section 3 argues that direct RI—RI that is not simply a derivative of some other, nonreferential instance of indeterminacy—is strictly incompatible with deflationism. Section 4 considers a couple of different ways the deflationist might try to achieve indirect RI—via indeterminate identity and indeterminate synonymy—and argues that each is unsatisfactory. (shrink)

We argue that distinct conditionals—conditionals that are governed by different logics—are needed to formalize the rules of Truth Introduction and Truth Elimination. We show that revision theory, when enriched with the new conditionals, yields an attractive theory of truth. We go on to compare this theory with one recently proposed by Hartry Field.

The category-theoretic representation of quantum event structures provides a canonical setting for confronting the fundamental problem of truth valuation in quantum mechanics as exemplified, in particular, by Kochen–Specker’s theorem. In the present study, this is realized on the basis of the existence of a categorical adjunction between the category of sheaves of variable local Boolean frames, constituting a topos, and the category of quantum event algebras. We show explicitly that the latter category is equipped with an object of truth values, (...) or classifying object, which constitutes the appropriate tool for assigning truth values to propositions describing the behavior of quantum systems. Effectively, this category-theoretic representation scheme circumvents consistently the semantic ambiguity with respect to truth valuation that is inherent in conventional quantum mechanics by inducing an objective contextual account of truth in the quantum domain of discourse. The philosophical implications of the resulting account are analyzed. We argue that it subscribes neither to a pragmatic instrumental nor to a relative notion of truth. Such an account essentially denies that there can be a universal context of reference or an Archimedean standpoint from which to evaluate logically the totality of facts of nature. (shrink)

In this paper we explain our pretense account of truth-talk and apply it in a diagnosis and treatment of the Liar Paradox. We begin by assuming that some form of deflationism is the correct approach to the topic of truth. We then briefly motivate the idea that all T-deflationists should endorse a fictionalist view of truth-talk, and, after distinguishing pretense-involving fictionalism (PIF) from error- theoretic fictionalism (ETF), explain the merits of the former over the latter. After presenting the basic framework (...) of our PIF account of truth-talk, we demonstrate a few advantages it offers over T-deflationist accounts that do not explicitly acknowledge pretense at work in the discourse. In turning to the Liar Paradox, we explain how the quasi-anaphoric functioning that our account attributes to truth-talk provides a diagnosis of the Liar Paradox (and other instances of semantic pathology) as having no content—in the sense of not specifying any of what we call M-conditions. At the same time, however, we vindicate the intuition that we can understand liar sentences, thereby avoiding one standard objection to “meaningless strategy” responses to the Liar Paradox. With this diagnosis in place, we then, by way of treatment, introduce a new predicate, ‘semantically defective’, and show how the explanation we give for its application allows for a consistent, yet revenge-immune, (dis)solution of the Liar Paradox, and semantic pathology generally. (shrink)

The logic of a physical theory reflects the structure of the propositions referring to the behaviour of a physical system in the domain of the relevant theory. It is argued in relation to classical mechanics that the propositional structure of the theory allows truth-value assignment in conformity with the traditional conception of a correspondence theory of truth. Every proposition in classical mechanics is assigned a definite truth value, either ‘true’ or ‘false’, describing what is actually the case at a certain (...) moment of time. Truth-value assignment in quantum mechanics, however, differs; it is known, by means of a variety of ‘no go’ theorems, that it is not possible to assign definite truth values to all propositions pertaining to a quantum system without generating a Kochen–Specker contradiction. In this respect, the Bub–Clifton ‘uniqueness theorem’ is utilized for arguing that truth-value definiteness is consistently restored with respect to a determinate sublattice of propositions defined by the state of the quantum system concerned and a particular observable to be measured. An account of truth of contextual correspondence is thereby provided that is appropriate to the quantum domain of discourse. The conceptual implications of the resulting account are traced down and analyzed at length. In this light, the traditional conception of correspondence truth may be viewed as a species or as a limit case of the more generic proposed scheme of contextual correspondence when the non-explicit specification of a context of discourse poses no further consequences. (shrink)

I argue that there is no metaphysically substantive property of truth. Although many take this thesis to be central to deflationism about truth, it is sometimes left unclear what a metaphysically substantive property of truth is supposed to be. I offer a precise account by relying on the distinction between the property and concept of truth. Metaphysical substantivism is the view that the property of truth is a sparse property, regardless of how one understands the nature of sparse properties. I (...) then offer two new arguments against metaphysical substantivism that employ ideas involving recombination and truthmaking. First, I argue that there are no theoretically compelling reasons to posit the existence of a metaphysically substantive property of truth. Secondly, I argue that if we do posit the existence of such a property, then we end up with a view that is either contradictory or unmotivated. What we’re left with is a metaphysically deflationary account of the property of truth that fully respects the metaphysical ambitions of truthmaker theory, and that is consistent with both the view that truth is a deflated, explanatorily impotent concept and the view that truth is an explanatorily powerful concept. (shrink)

In this paper, I discuss two concerns for pluralist truth theories: a concern about a key detail of these theories and a concern about their viability. The detail-related concern is that pluralists have relied heavily upon the notion of a domain, but it is not transparent what they take domains to be. Since the notion of a domain has been present in philosophy for some time, it is important for many theorists, not only truth pluralists, to be clear on what (...) domains are and what work they can do. The viability-related concern is that it’s not clear how a pluralist truth theory could explain the truth-conditions of mixed atomic propositions. To address this concern, truth pluralists should recognize something to which they have not been sufficiently attentive: that some atomic propositions belong to more than one domain. But, recognizing this requires rethinking the relationships between the nature of propositions, their membership in domains, and their truth. I address these issues and propose an understanding of them that is preferable to the best existing account of them, that offered by Michael Lynch. (shrink)

In this article, I provide a general account of deflationism. After doing so, I turn to truth-defla- tionism, where, after first describing some of the species, I highlight some challenges for those who wish to adopt it.

This anthology of the very latest research on truth features the work of recognized luminaries in the field, put together following a rigorous refereeing process. Along with an introduction outlining the central issues in the field, it provides a unique and unrivaled view of contemporary work on the nature of truth, with papers selected from key conferences in 2011 such as Truth Be Told, Truth at Work, Paradoxes of Truth and Denotation and Axiomatic Theories of Truth. Studying the nature of (...) the concept of ‘truth’ has always been a core role of philosophy, but recent years have been a boom time in the topic. With a wealth of recent conferences examining the subject from various angles, this collection of essays recognizes the pressing need for a volume that brings scholars up to date on the arguments. Offering academics and graduate students alike a much-needed repository of today’s cutting-edge work in this vital topic of philosophy, the volume is required reading for anyone needing to keep abreast of developments, and is certain to act as a catalyst for further innovation and research. (shrink)

The laws of logic and two of the broader theories of truth are fundamental components that are responsible for espousing an ontology and meaningfulness in matters of analytic philosophy. In this respect they have persisted as conventional attitudes or modes of thought which most, if not all, of analytic philosophy uses to philosophize. However, despite the conceptual productivity of these components they are unable to account for matters that are beyond them. These matters would include certain theological beliefs, for instance, (...) that transcend the purview of analytic ontology and the meaningfulness it ensues. Any attempt in making rational sense of such beliefs that are insusceptible to these methodological components would conventionally prohibit (restrict) us from rationally believing in them. This is because we would be unable to make sense of such beliefs with the aid of these methodological components. As a result of this, religious beliefs of this particular nature would be deemed irrational. I shall demonstrate this point by applying both of these components to an absolutely ineffable God of Islam. This would entail, attempting to make sense of an absolutely ineffable God of Islam in virtue of the laws of logic and two broad categories of truth theories, namely, substantive and insubstantive theories. I hope to establish that applying both of these methodological components in attempting to make sense of an absolutely ineffable God of Islam would not be conceptually viable. It would result in a contradictory notion which I shall allude to as the paradox of ineffability. (shrink)

Recently, several philosophers have proposed fictionalist accounts of truth-talk, as a means for resolving the semantic pathology that the Liar Paradox appears to present. These alethic fictionalists aim to vindicate truth-talk as a kind of as if discourse, while rejecting that the talk attributes any real property of truth. Liggins has recently critically assessed one such proposal, Beall’s constructive methodological deflationist, offering objections to Beall’s proposed alethic fictionalism that potentially generalize to other alethic fictionalist accounts. Liggins further argues that CMD (...) supports a classically consistent response to the Liar Paradox—one that can be extracted from CMD, while leaving its putatively problematic fictionalist elements behind in favor of alethic nihilism. In this paper, after establishing that Liggins’s criticisms of CMD are off base, we show that the classical resolution of the Liar Paradox that he proposes is unworkable. Since his resistance to alethic fictionalism turns out to be unmotivated, we conclude that this approach is still worth considering as a framework for a resolution of the Liar Paradox. (shrink)

From antiquity several philosophers have claimed that the goal of natural science is truth. In particular, this is a basic tenet of contemporary scientific realism. However, all concepts of truth that have been put forward are inadequate to modern science because they do not provide a criterion of truth. This means that we will generally be unable to recognize a scientific truth when we reach it. As an alternative, this paper argues that the goal of natural science is plausibility and (...) considers some characters of plausibility. (shrink)

In the philosophy of Alain Badiou, ethics can only arise in relation to an evental truth procedure that breaks from the economic logic of a situation. Further, because for Badiou there cannot be economic truths per se – rather, economic matters must be understood in their relation to one or more truths in the domain of love, art, science or politics – a Badiouian business ethics would look entirely distinct from any ethics that simply places limits on certain kinds of (...) economic activity. Although Slavoj Žižek, among others, has suggested that this marks an essential weakness in Badiou's economic/political theory, it may actually be the greatest strength of his position. Within a capitalist system, a Badiouian business ethics would then be a question of mobilizing economic resources in order to serve the ongoing construction of a truth procedure. For a business to be considered ethical on Badiou's terms, it must break – and continue to break – from the dominant logic of capitalism and its merely economic pursuit of profit maximization. (shrink)

ABSTRACT What do we disagree about when we disagree about logic? On the face of it, classical and nonclassical logicians disagree about the laws of logic and the nature of logical properties. Yet, sometimes the parties are accused of talking past each other. The worry is that if the parties to the dispute do not mean the same thing with ‘if’, ‘or’, and ‘not’, they fail to have genuine disagreement about the laws in question. After the work of Quine, this (...) objection against genuine disagreement about logic has been called the meaning-variance thesis. We argue that the meaning-variance thesis can be endorsed without blocking genuine disagreement. In fact, even the type of revisionism and nonapriorism championed by Quine turns out to be compatible with meaning-variance. (shrink)

In a recent article, David distinguishes between two interpretations of Tarski’s work on truth. The standard interpretation has it that Tarski gave us a definition of truth in-L within the meta-language; the non-standard interpretation, that Tarski did not give us a definition of true sentence in L, but rather a definition of truth, and Tarski does so for L within the metalanguage. The difference is crucial: for on the standard view, there are different concepts of truth, while in the alternative (...) interpretation there is just one concept. In this paper we will have a brief look at the distinction between these two interpretations and at the arguments David gives for each view. We will evaluate one of David’s arguments for the alternative view by looking at Tarski’s ‘On the concept of truth in formalized languages’, and his use of the term ‘extension’ therein, which, we shall find, yields no conclusive evidence for either position. Then we will look at how Tarski treats ‘satisfaction’, an essential concept for his definition of ‘true sentence’. It will be argued that, in light of how Tarski talks about ‘satisfaction’ in Sect. 4 of ‘CTF’ and his claims in the Postscript, the alternative view is more likely than the standard one. (shrink)

First paragraph: This paper seeks to understand various paradoxes as cases of conflicting rules. In particular, the ambition is to outline a new perspective on and response to the Liar -- though it will take us a while to get that far. We begin in Section 1 with an account of simple rule confliction. Section 2 then brings this account to bear on a paradox, the Secretary Liberation Paradox, which is readily seen to involve conflicting rules. Finally in Section 3 (...) I suggest that the Liar can also be seen as a case of rule confliction, and outline briefly how that perspective provides for Liar arguments to be blocked. (shrink)

This brief, largely expository book—hereafter TT—blends history and philosophy of logic with contemporary mathematical logic. Page 3 says it “is about the relation between formal theories of truth...

Letting is a common practice in mathematics. For example, we let x be the sum of the first n integers and, after a short proof, conclude that x = n(n+1)/2; we let J be the point where the bisectors of two of the angles of a triangle intersect and prove that this coincides with H, the point at which another pair of bisectors of the angles of that triangle intersect. Karl Weierstrass's colleagues, in an attempt to solve optimization problems, stipulated (...) that the minimum area for a triangle with a given perimeter be a straight line segment conceived as a triangle with zero altitude. (Weierstrass complained that this obscured the insight that some problems have no solutions.) In mathematics applied to physics, we let x be the temperature in Fahrenheit corresponding to 30° Centigrade; we let v be the velocity of the Earth through the luminiferous ether. Before the error was spotted, the official rules for Little League Baseball made an inconsistent stipulation about the dimensions of home plate (Bradley 1996). (shrink)