Pure second-order logic is second-order logic without functional or first-order variables. In "Pure Second-Order Logic," Denyer shows that pure second-order logic is compact and that its notion of logical truth is decidable. However, his argument does not extend to pure second-order logic with second-order identity. We give a more general argument, based on elimination of quantifiers, which shows that any formula of pure second-order logic with (...) second-order identity is equivalent to a member of a circumscribed class of formulas. As a corollary, pure second-order logic with second-order identity is compact, its notion of logical truth is decidable, and it satisfies a pure second-order analogue of model completeness. We end by mentioning an extension to n th-order pure logics. (shrink)

Quine’s most important charge against second-, and more generally, higher-order logic is that it carries massive existential commitments. The force of this charge does not depend upon Quine’s questionable assimilation of second-order logic to set theory. Even if we take second-order variables to range over properties, rather than sets, the charge remains in force, as long as properties are individuated purely extensionally. I argue that if we interpret them as ranging over properties more reasonably (...) construed, in accordance with an abundant or deflationary conception, Quine’s charge can be resisted. This interpretation need not be seen as precluding the use of model-theoretic semantics for second-order languages; but it will preclude the use of the standard semantics, along with the more general Henkin semantics, of which it is a special case. To that extent, the approach I recommend has revisionary implications which some may find unpalatable; it is, however, compatible with the quite different special case in which the second-order variables are taken to range over definable subsets of the first-order domain, and with respect to such a semantics, some important metalogical results obtainable under the standard semantics may still be obtained. In my final section, I discuss the relations between second-order logic, interpreted as I recommend, and a strong version of schematic ancestral logic promoted in recent work by Richard Heck. I argue that while there is an interpretation on which Heck’s logic can be contrasted with second-order logic as standardly interpreted, when it is so interpreted, its differences from the more modest form of second-order logic I advocate are much less substantial, and may be largely presentational. (shrink)

We examine second order intuitionistic propositional logic, IPC². Let $F_\exists $ be the set of formulas with no universal quantification. We prove Glivenko's theorem for formulas in $F_\exists $ that is, for φ € $F_\exists $ φ is a classical tautology if and only if ¬¬φ is a tautology of IPC². We show that for each sentence φ € $F_\exists $ (without free variables), φ is a classical tautology if and only if φ is an intuitionistic tautology. As (...) a corollary we obtain a semantic argument that the quantifier V is not definable in IPC² from ⊥, V, ^, →. (shrink)

A second-order preference is a preference over preferences. This paper addresses the role that second-order preferences play in a theory of instrumental rationality. I argue that second-order preferences have no role to play in the prescription or evaluation of actions aimed at ordinary ends. Instead, second-order preferences are relevant to prescribing or evaluating actions only insofar as those actions have a role in changing or maintaining first-order preferences. I establish these claims (...) by examining and rejecting the view that second-order preferences trump first-order preferences. I also examine and reject the view that second-order preferences give additional normative force to an agent’s preferred first-order preferences. I conclude by arguing that second-order preferences should be integrated into an agent’s object-level preference ordering, and by explaining how best to make sense of this integration. (shrink)

Context: Philosophy of science is the branch of philosophy that deals with methods, foundations, and implications of science. It is a theory of how to create scientific knowledge. Presently, there is widespread agreement on how to do science, namely conjectures, ideally in the form of a mathematical model, and refutations, testing the model using empirical evidence. Problem: Many social scientists are using a conception of science created for the physical sciences. Expanding philosophy of science so that it more successfully encompasses (...) social systems would create new avenues of inquiry. Two dimensions could be added to philosophy of science: the amount of attention paid to the observer and the amount of impact of a theory on the system described. Method: My approach is to illuminate underlying assumptions. I claim that there are at least three epistemologies and that they can be combined to form a more robust conception of knowledge and of how to do research. There are at least four models and four basic elements being used by scientists. Results: The article identifies the logical propositions underlying second-order science. It suggests strategies for developing second-order science. And it describes several methods that can be used to practice second-order science, including how past theories have not only described but also changed the phenomenon being studied. Implications: The task for members of the scientific community, particularly social scientists, is to practice second-order science and to develop further its theories and methods. A practical implication is to accept methods for acting as well as theories as a contribution to science, since methods explicitly define the role of an observer/ participant. Constructivist content: The paper is an extension of the work of Heinz von Foerster and other second-order cyberneticians. (shrink)

Intuitionistic dependence logic was introduced by Abramsky and Väänänen [1] as a variant of dependence logic under a general construction of Hodges’ (trump) team semantics. It was proven that there is a translation from intuitionistic dependence logic sentences into second order logic sentences. In this paper, we prove that the other direction is also true, therefore intuitionistic dependence logic is equivalent to second order logic on the level of sentences.

Clarke and Beck argue that the ANS doesn't represent non-numerical magnitudes because of its second-order character. A sensory integration mechanism can explain this character as well, provided the dumbbell studies involve interference from systems that segment by objects such as the Object Tracking System. Although currently equal hypotheses, I point to several ways the two can be distinguished.

The logic of paradox, LP, is a first-order, three-valued logic that has been advocated by Graham Priest as an appropriate way to represent the possibility of acceptable contradictory statements. Second-order LP is that logic augmented with quantification over predicates. As with classical second-order logic, there are different ways to give the semantic interpretation of sentences of the logic. The different ways give rise to different logical advantages and disadvantages, and we canvass several of these, concluding (...) that it will be extremely difficult to appeal to second-order LP for the purposes that its proponents advocate, until some deep, intricate, and hitherto unarticulated metaphysical advances are made. (shrink)

We prove that every monadic second-order property of the unfolding of a transition system is a monadic second-order property of the system itself. An unfolding is an instance of the general notion of graph covering. We consider two more instances of this notion. A similar result is possible for one of them but not for the other.

Psychological game theory, as defined by Colman, is meant to offer a series of solution concepts that should reduce the indeterminacy of orthodox game theory when applied to a series of situations. My main criticism is that, actually, they introduce a second-order indeterminacy problem rather than offering a viable solution. The reason is that the proposed solution concepts are under-specified in their definition and in their scope.

Sellars [1960, ‘Grammar and existence: A preface to ontology’] argues that the truth of a second-order sentence does not incur commitment to there being any sort of abstract entity. This paper begins by exploring the arguments that Sellars offers for the above claim. It then develops those arguments by pointing out places where Sellars has been unclear or ought to have said more. In particular, Sellars's arguments rely on there being a means by which language users could come (...) to understand sentences of a second-order language wherein the truth of second-order existential sentences do not require there to be abstract entities. In addition to this, as Sellars [1979, Naturalism and Ontology] notes, a formal account of quantification is required that does not make use of the apparatus of sequences. Both such a translation of and a formal account of quantification are provided in this article. (shrink)

Differential equations of second order appear in physical applications such as fluid dynamics, electromagnetism, acoustic vibrations, and quantum mechanics. In this paper, necessary and sufficient conditions are established of the solutions to second-order half-linear delay differential equations of the form ς y u ′ y a ′ + ∑ j = 1 m p j y u c j ϑ j y = 0 for y ≥ y 0, under the assumption ∫ ∞ ς η − (...) 1 / a d η = ∞. We consider two cases when a c j, where a and c j are the quotient of two positive odd integers. Two examples are given to show effectiveness and applicability of the result. (shrink)

Open peer commentary on the article “Second-Order Science: Logic, Strategies, Methods” by Stuart A. Umpleby. Upshot: Umpleby’s approach to second-order science is top-down, and as such, fails to distinguish the cognitive mechanisms that provide the direct enacted link between such science and constructivism. When the idea of “ceteris paribus” holds little meaning to the examined situation, we are in the realm of second-order science, or Science 2. Only Science 2 can deal with emergence, volition, (...) and reflexive anticipation. These three properties are how constructivism gets enacted and provide the foundation upon which Science 2 inquiries rest. (shrink)

This paper investigates whether there is an acceptable version of Functionalism that avoids commitment to second-order properties. I argue that the answer is "no". I consider two reductionist versions of Functionalism, and argue that both are compatible with multiple realization as such. There is a more specific type of multiple realization that poses difficulties for these views, however. The only apparent Functionalist solution is to accept second-order properties.

Second-order quantifier elimination in the context of classical logic emerged as a powerful technique in many applications, including the correspondence theory, relational databases, deductive and knowledge databases, knowledge representation, commonsense reasoning and approximate reasoning. In the current paper we first generalize the result of Nonnengart and Szałas [17] by allowing second-order variables to appear within higher-order contexts. Then we focus on a semantical analysis of conditionals, using the introduced technique and Gabbay’s semantics provided in [10] (...) and substantially using a third-order accessibility relation. The analysis is done via finding correspondences between axioms involving conditionals and properties of the underlying third-order relation. (shrink)

In the first part of the text the distinction between first- and second-order impartiality, along with Brian Barry?s thorough elaboration of their characteristics and the differences between them, is examined. While the former impartiality is related to non-favoring fellow-persons in everyday occasions, the latter is manifested in the institutional structure of society and its political and public morality. In the second part of the article, the concept of public impartiality is introduced through analysis of two examples. In (...) the first example, a Caledonian Club with its exclusive membership is considered as a form of association which is partial, but nevertheless morally acceptable. In the second example, the so-called Heinz dilemma has been reconsidered and the author points to some flaws in Barry?s interpretation, arguing that Heinz?s right of giving advantage to his wife?s life over property rights can be recognized through mitigating circum-stances, and this partiality can be appreciated in the public sphere. Thus, public impartiality imposes limits to the restrictiveness and rigidity of political impartiality implied in second-order morality. (shrink)

The characterization of second-order type isomorphisms is a purely syntactical problem that we propose to study under the enlightenment of game semantics. We study this question in the case of second-order λμ-calculus, which can be seen as an extension of system F to classical logic, and for which we define a categorical framework: control hyperdoctrines.Our game model of λμ-calculus is based on polymorphic arenas which evolve during the play. We show that type isomorphisms coincide with the (...) “equality” on arenas associated with types. Finally we deduce the equational characterization of type isomorphisms from this equality. We also recover from the same model Roberto Di Cosmo’s characterization of type isomorphisms for system F.This approach leads to a geometrical comprehension on the question of second-order type isomorphisms, which can be easily extended to some other polymorphic calculi including additional programming features. (shrink)

This paper explores the thesis that the concept of cultural techniques should be strictly limited to symbolic technologies that allow for self-referential recursions. Writing enables one to write about writing itself; painting itself can be depicted in painting; films may feature other films. In other words, cultural techniques are defined by their ability to thematize themselves; they are second-order techniques as opposed to first-order techniques like cooking or tilling a field. To illustrate his thesis, Macho discusses a (...) sequence of historical examples, from body signs and death masks to digital code and ID papers. These examples serve to reiterate another basic proposal that is already announced in the paper’s title. The recursive, self-observing qualities of cultural techniques make them a ‘technology of the self’ and thus render them indispensable for the generation, repetition and maintenance of identity. (shrink)

The algebraic structure of the 8-spinor formalism is discussed, and the general form of the 8-component wave equation, equivalent to the second-order 4-component one, is presented. This allows a canonical formulation that will be the first stage of the future Clebsch parametrization, i.e., a relativistic generalization of the Bohm-Schiller-Tiomno pioneering work on the Pauli equation.

In this paper, I shall provide a defence of second-order logic in the context of its use in the philosophy of mathematics. This shall be done by considering three problems that have been recently posed against this logic: (1) According to Resnik [1988], by adopting second-order quantifiers, we become ontologically committed to classes. (2) As opposed to what is claimed by defenders of second-order logic (such as Shapiro [1985]), the existence of non-standard models of (...) first-order theories does not establish the inadequacy of first—order axiomatisations (Melia [1995]). (3) In contrast with Shapiro’s suggestion (in his [1985]), second-order logic does not help us to establish referential access to mathematical objects (Azzouni [1994]). As I shall argue, each of these problems can be neatly solved by the second-order theorist. As a result, a case for second-order logic can be made. The first two problems will beconsidered rather briefly in the next section. The rest of the paper is dedicate to a discussion of the third. (shrink)

Open peer commentary on the article “On Climate Change Research, the Crisis of Science and Second-order Science” by Philipp Aufenvenne, Heike Egner & Kirsten von Elverfeldt. Upshot: Bringing second-order understandings to the doing of climate science is to be welcomed. In taking a second-order turn, it is imperative to reflect on reflection, or report authentically our doings and thus move beyond sterile debates about what ought to be or what second-order doings are (...) or are not. The field of doing second-order R&D is not a terra nullius, so exploring the full range and domains of praxis is warranted. (shrink)

In this paper we investigate several extensions of the first order-language with finitely many binary relations. The most interesting of the studied extensions appears to be the monadic second-order one. We show that the extended languages have the same expressive power as the first-order language over the class of all relational structures of equivalence relations in local agreement by providing appropriate translation of formulae. The decidability of the considered extensions over the above mentioned class of structures (...) is also shown. (shrink)

Some recent views of action have claimed that a correct conceptual account of action must include second-order motivational states. This follows from the fact that first-order motivational states such as desires account for action or mere behavior in which the agent's participation is lacking; thus, first-order motivational states cannot by themselves account for action in which the agent participates, so-called full-blooded action. I argue that representing the agent's participation by means of second-order states is (...) bound to fail because it misrepresents what an agent is doing when acting in the full-blooded sense. I begin by characterizing full-blooded action and explaining the failure of first-order accounts to explain it. I next show that while second-order accounts have some success in explaining full-blooded action, they fail to distinguish it from action which exhibits motivational alienation. I then argue that even if this problem were resolved, the second-order accounts more fundamentally misrepresent full-blooded action by depicting such action in an introverted manner. I conclude by considering a sketch of agency and full-blooded action that does not rely on second-order states and by addressing a primary concern thought to favor the second-order accounts, the concern of agent causation. (shrink)

Open peer commentary on the article “Second-Order Science: Logic, Strategies, Methods” by Stuart A. Umpleby. Upshot: Second-order science requires a specific methodology. It thereby reverses the classical observer-observed relation in favor of the observed - i.e., the first-order observers - if the principle of autopoiesis is acknowledged.

We discuss the differences between first-order set theory and second-order logic as a foundation for mathematics. We analyse these languages in terms of two levels of formalization. The analysis shows that if second-order logic is understood in its full semantics capable of characterizing categorically central mathematical concepts, it relies entirely on informal reasoning. On the other hand, if it is given a weak semantics, it loses its power in expressing concepts categorically. First-order set theory (...) and second-order logic are not radically different: the latter is a major fragment of the former. (shrink)

Open peer commentary on the article “Constructivist Model Building: Empirical Examples From Mathematics Education” by Catherine Ulrich, Erik S. Tillema, Amy J. Hackenberg & Anderson Norton. Upshot: I address the value of Ulrich et al.’s distinction between three types of second-order models. I conclude that their work contributes to the theorizing of adaptive teaching on the basis of a constructivist stance on knowing and learning.

Is second-order logic logic? Famously Quine argued second-order logic wasn't logic but his arguments have been the subject of influential criticisms. In the early sections of this paper, I develop a deeper perspective upon Quine's philosophy of logic by exploring his positive conception of what logic is for and hence what logic is. Seen from this perspective, I argue that many of the criticisms of his case against second-order logic miss their mark. Then, in (...) the later sections, I go beyond Quine to develop a novel case that quantification into polyadic predicate position, understood as requiring quantifiers to range over relations, isn't intelligible. (shrink)

We study reflection principles in Kelley-Morse set theory with urelements (KMU). We first show that First-Order Reflection Principle is not provable in KMU with Global Choice. We then show that KMU + Limitation of Size + Second-Order Reflection Principle is mutually interpretable with KM + Second-Order Reflection Principle. Furthermore, these two theories are also shown to be bi-interpretable with parameters. Finally, assuming the existence of a κ+-supercompact cardinal κ in KMU, we construct a model of (...) KMU + Second-Order Reflection Principle where Limitation of Size fails. (shrink)

This paper examines the ontological commitments of the second-order language of arithmetic and argues that they do not extend beyond the first-order language. Then, building on an argument by George Boolos, we develop a Tarski-style definition of a truth predicate for the second-order language of arithmetic that does not involve the assignment of sets to second-order variables but rather uses the same class of assignments standardly used in a definition for the first-order (...) language. (shrink)

Taking the example of the Basel carnival Fasnacht, the paper shows in what way ritual can maintain the impression of being traditional and unchanging, and yet be open to changes and innovations. As the basic conceptual framework we use the notion of liminality, which Victor Turner identified as the creative moment of ritual. In Fasnacht, this liminal dimension appears in two degrees. The carnival as such represents a reflexive liminal counterpart to the standard social structure, yet it is itself also (...) highly structured and bound by conservative traditional rules. As a reaction to this, there arises within Fasnacht a second-order liminality in the form of the so-called wild Fasnacht, which turns the official antistructural Fasnacht rules upside down once again, testing their validity. While the carnival structure offers a regulated opportunity for questioning everyday social behaviour, wild Fasnacht questions even this regulated manner of questioning as such, opening space for its reflection and modification. We use detailed examples to demonstrate how the subtle dialectics of structure and antistructure keeps the tradition of Basel’s Fasnacht alive and allows it to evolve without destroying its aura of traditionality. (shrink)

We study definability of second-order generalized quantifiers. We show that the question whether a second-order generalized quantifier $\sQ_1$ is definable in terms of another quantifier $\sQ_2$, the base logic being monadic second-order logic, reduces to the question if a quantifier $\sQ^{\star}_1$ is definable in $\FO(\sQ^{\star}_2,<,+,\times)$ for certain first-order quantifiers $\sQ^{\star}_1$ and $\sQ^{\star}_2$. We use our characterization to show new definability and non-definability results for second-order generalized quantifiers. In particular, we show that (...) the monadic second-order majority quantifier $\most^1$ is not definable in second-order logic. (shrink)

The traditional sciences often bracket away ambiguity through the imposition of “enabling constraints”—making a set of assumptions and then declaring ceteris paribus. These enabling constraints take the form of uncritically examined presuppositions or “uceps.” Second order science reveals hidden issues, problems and assumptions which all too often escape the attention of the practicing scientist. These hidden values—precisely because they are hidden and not made explicit—can get in the way of the public’s acceptance of a scientific claim. A conflict (...) in understood meaning—between the scientist’s restricted claims and the public’s broader understanding of those same claims can result in cognitive dissonance or the equivalent of the Mori Uncanny Valley. Scientists often react to these differences by claiming “incommensurability” between their restricted claim and the public’s understanding. Second order science, by explicating the effects of variations in values assumed for these uceps and associated impacts on related scientific claims, can often moot these assertions of incommensurability and thereby promote greater scientific understanding. This article explores how second order science can address issues of public doubt regarding the scientific enterprise using examples from medicine, diet and climate science. (shrink)

A second-order conspiracy (SOC) is a conspiracy that aims to create (and typically also disseminate) a conspiracy theory. Second-order conspiracy theories (SOCT) are theories that explain the occurrence of a given conspiracy theory by appeal to a conspiracy. In this paper I argue that SOC and SOCT are useful and coherent concepts, while also having numerous philosophically interesting upshots (in terms of epistemology, explanation, and prediction). Secondly, I appeal to the nature of two specific kinds of (...) second-order conspiracies to make the case for what has been called ‘local generalism’ (Stamatiadis-Bréhier 2023a). Specifically, I focus on so-called ‘denial industries’ to argue that the structure of these second-order conspiracies allows us to infer non-accidental generalisations about the domain of conspiracy theories. Even though it is true that there is nothing epistemically problematic with the general class of conspiracy theories, there are specific subsets of conspiracy theories that warrant immediate strong suspicion (cf. Dentith 2022). By looking at the intricate mechanisms by which these denial industries operate, we can infer that the conspiracy theories that are produced by them are epistemically unwarranted. I conclude by making some exploratory remarks about what the metaphysics of second-order conspiracies would look like. (shrink)

We study elementary second order extensions of the theoryID 1 of non-iterated inductive definitions and the theoryPA Ω of Peano arithmetic with ordinals. We determine the exact proof-theoretic strength of those extensions and their natural subsystems, and we relate them to subsystems of analysis with arithmetic comprehension plusΠ 1 1 comprehension and bar induction without set parameters.

When laypersons are presented with scientific information which seeks to modify their way of life, they are expected to believe, suspend belief, or reject it. Second-order assessment of scientific experts helps laypersons to make an informed decision in such situations. This is an assessment of the trustworthiness of the person making the scientific claim. In this paper I challenge the optimistic view of Anderson (2011), regarding the ease with which laypersons can perform second-order assessment of experts, (...) by pointing out some of the obstacles that may prevent laypersons from arriving at an informed decision through this means. By showing that laypersons cannot easily perform second-order assessment of experts, I make a case for sharing epistemic burdens in science communication by using Lackey's (2006) concept of dualism in the epistemology of testimony and Irzik and Kurtulmus’ (2019) work on public epistemic trust in science, as a guide. I invite experts to bear a greater share of the epistemic burden when communicating with laypersons because of their privileged epistemic condition vis-à-vis laypersons. (shrink)

The second order intuitionistic propositional logic characterized by the class of all “principal” Kripke frames is non-recursively axiomatizable, as well as any logic of a class of principal Kripke frames containing every finite frame.

Following [3], we build higher-order models of analysis resembling the frameworks of nonstandard analysis. The models are entirely canonical, constructed without Choice. Weak transfer principles are developed and the models are applied to topology, graph theory, and measure theory. A Loeb-like measure is constructed.

We study the Lindenbaum algebra ${\fancyscript{A}}$ (WKL o, RCA o) of sentences in the language of second-order arithmetic that imply RCA o and are provable from WKL o. We explore the relationship between ${\Sigma^1_1}$ sentences in ${\fancyscript{A}}$ (WKL o, RCA o) and ${\Pi^0_1}$ classes of subsets of ω. By applying a result of Binns and Simpson (Arch. Math. Logic 43(3), 399–414, 2004) about ${\Pi^0_1}$ classes, we give a specific embedding of the free distributive lattice with countably many generators (...) into ${\fancyscript{A}}$ (WKL o, RCA o). (shrink)

“Second-order Logic” in Anderson, C.A. and Zeleny, M., Eds. Logic, Meaning, and Computation: Essays in Memory of Alonzo Church. Dordrecht: Kluwer, 2001. Pp. 61–76. -/- Abstract. This expository article focuses on the fundamental differences between second- order logic and first-order logic. It is written entirely in ordinary English without logical symbols. It employs second-order propositions and second-order reasoning in a natural way to illustrate the fact that second-order logic is (...) actually a familiar part of our traditional intuitive logical framework and that it is not an artificial formalism created by specialists for technical purposes. To illustrate some of the main relationships between second-order logic and first-order logic, this paper introduces basic logic, a kind of zero-order logic, which is more rudimentary than first-order and which is transcended by first-order in the same way that first-order is transcended by second-order. The heuristic effectiveness and the historical importance of second-order logic are reviewed in the context of the contemporary debate over the legitimacy of second-order logic. Rejection of second-order logic is viewed as radical: an incipient paradigm shift involving radical repudiation of a part of our scientific tradition, a tradition that is defended by classical logicians. But it is also viewed as reactionary: as being analogous to the reactionary repudiation of symbolic logic by supporters of “Aristotelian” traditional logic. But even if “genuine” logic comes to be regarded as excluding second-order reasoning, which seems less likely today than fifty years ago, its effectiveness as a heuristic instrument will remain and its importance for understanding the history of logic and mathematics will not be diminished. Second-order logic may someday be gone, but it will never be forgotten. Technical formalisms have been avoided entirely in an effort to reach a wide audience, but every effort has been made to limit the inevitable sacrifice of rigor. People who do not know second-order logic cannot understand the modern debate over its legitimacy and they are cut-off from the heuristic advantages of second-order logic. And, what may be worse, they are cut-off from an understanding of the history of logic and thus are constrained to have distorted views of the nature of the subject. As Aristotle first said, we do not understand a discipline until we have seen its development. It is a truism that a person's conceptions of what a discipline is and of what it can become are predicated on their conception of what it has been. (shrink)

Second or higher order probabilities have commonly been viewed with scepticism by those working within the realm of probability and decision theory. The aim of the present note is to show how the notion of second order probabilities can add to our understanding of judgmental and decision processes and how the traditional framework of Bayesian decision theory can be extended in a fruitful way by taking such entities into account. Section one consists of a brief account (...) of arguments put forth against higher order probabilities as well as of counterarguments. In order to provide an example of the applicability of second order probabilities a decision theory encompassing such probabilities will be presented in section two. In section three I will try to emphasize the value of second order probabilities for a deeper and more complete understanding of the notion of risk. (shrink)

This dissertation develops an inferentialist theory of meaning. It takes as a starting point that the sense of a sentence is determined by the rules governing its use. In particular, there are two features of the use of a sentence that jointly determine its sense, the conditions under which it is coherent to assert that sentence and the conditions under which it is coherent to deny that sentence. From this starting point the dissertation develops a theory of quantification as marking (...) coherent ways a language can be expanded and modality as the means by which we can reflect on the norms governing the assertion and denial conditions of our language. If the view of quantification that is argued for is correct, then there is no tension between second-order quantification and nominalism. In particular, the ontological commitments one can incur through the use of a quantifier depend wholly on the ontological commitments one can incur through the use of atomic sentences. The dissertation concludes by applying the developed theory of meaning to the metaphysical issue of necessitism and contingentism. Two objections to a logic of contingentism are raised and addressed. The resulting logic is shown to meet all the requirement that the dissertation lays out for a theory of meaning for quantifiers and modal operators. (shrink)

A normative reason for a person to? is a consideration which favours?ing. A motivating reason is a reason for which or on the basis of which a person?s. This paper explores a connection between normative and motivating reasons. More specifically, it explores the idea that there are second-order normative reasons to? for or on the basis of certain first-order normative reasons. In this paper, I challenge the view that there are second-order reasons so understood. I (...) then show that prominent views in contemporary epistemology are committed to the existence of second-order reasons, specifically, views about the epistemic norms governing practical reasoning and about the role of higher-order evidence. If there are no second-order reasons, those views are mistaken. (shrink)

Second-order logic has a number of attractive features, in particular the strong expressive resources it offers, and the possibility of articulating categorical mathematical theories (such as arithmetic and analysis). But it also has its costs. Five major charges have been launched against second-order logic: (1) It is not axiomatizable; as opposed to first-order logic, it is inherently incomplete. (2) It also has several semantics, and there is no criterion to choose between them (Putnam, J Symbol (...) Logic 45:464–482, 1980 ). Therefore, it is not clear how this logic should be interpreted. (3) Second-order logic also has strong ontological commitments: (a) it is ontologically committed to classes (Resnik, J Phil 85:75–87, 1988 ), and (b) according to Quine (Philosophy of logic, Prentice-Hall: Englewood Cliffs, 1970 ), it is nothing more than “set theory in sheep’s clothing”. (4) It is also not better than its first-order counterpart, in the following sense: if first-order logic does not characterize adequately mathematical systems, given the existence of non - isomorphic first-order interpretations, second-order logic does not characterize them either, given the existence of different interpretations of second-order theories (Melia, Analysis 55:127–134, 1995 ). (5) Finally, as opposed to what is claimed by defenders of second-order logic [such as Shapiro (J Symbol Logic 50:714–742, 1985 )], this logic does not solve the problem of referential access to mathematical objects (Azzouni, Metaphysical myths, mathematical practice: the logic and epistemology of the exact sciences, Cambridge University Press, Cambridge, 1994 ). In this paper, I argue that the second-order theorist can solve each of these difficulties. As a result, second-order logic provides the benefits of a rich framework without the associated costs. (shrink)

Resumen En una serie de escritos Timothy Williamson ha argumentado a favor del necesitismo, esto es, la tesis de que es necesario que todo exista necesariamente. Este trabajo discute el necesitismo de segundo orden, esto es, la tesis de que es necesario que toda propiedad exista necesariamente, considerando líneas de argumentación semejantes a las desplegadas en primer orden. Se examinan tres de estos argumentos: el carácter necesario de ser una propiedad, la aparición de las propiedades en proposiciones, y los compromisos (...) ontológicos del metalenguaje en el que se formula la semántica. Se argumenta que ninguno de ellos es realmente convincente. La justificación del necesitismo de segundo orden parece requerir más metafísica sustantiva que resultados formales, al menos si es que los resultados formales de que se trata son aquellos discutidos aquí.In a series of writings Timothy Williamson has argued for necessitism, i. e. the thesis that it is necessary that everything exists necessarily. This work discusses second-order necessitism, i. e. the thesis that it is necessary that every property exists necessarily, considering lines of argument similar to those displayed on first-order. Three of those arguments are examined. the necessary character ofbeing a property, the occurrence of properties in propositions, and the ontological commitments of the metalanguage where the semantics is formulated. It is argued that none of them are compelling. The justification for second-order necessitism seems to require more substantive metaphysics than formal results, at least if the formal results in view are those discussed here. (shrink)

Philosophers who work on desert-adjustment within axiology often articulate the concept of desert as follows: x deserves y on the basis of z. This formulation allows for a focused examination that encompasses deservers, deservings, and desert bases. I call this first-order desert. This paper posits that axiology grounded solely in first-order desert fails to adequately capture our nuanced intuitions concerning desert. I contend that to construct an axiology that more effectively aligns with our desert-sensitive intuitions, we must incorporate (...) considerations of second-order desert. Second-order desert is defined as follows: x deserves to live a life in which x deserves y on the basis of z. Initially, I provide a definition of first-order desert, followed by an elucidation of second-order desert. Subsequently, I explore various counter-arguments against my proposition. I defend my proposal against potential counter-arguments, demonstrating that a desert-adjusted axiological theory will be significantly better-off by incorporating second-order desert considerations. (shrink)

Under a weak set-theoretic assumption we interpret second-order logic in the monadic theory of order.

In the language of second-order logic, first- and second-order variables are distinguished syntactically and cannot be grammatically substituted. According to a prominent argument for the deployment of these languages, these substitution failures are necessary to block the derivation of paradoxes that result from attempts to generalize over predicate interpretations. I first examine previous approaches which interpret second-order sentences using expressions of natural language and argue that these approaches undermine these syntactic restrictions. I then examine (...) Williamson’s primitivist approach according to which second-order sentences are not offered readings in a previously understood language. I argue that the syntactic restrictions alone do not block the derivation of the paradox, unless they are backed by a principled reason that the language cannot be expanded to allow the grammatical substitution of first- and second- order variables. I argue that there is neither a syntactic nor a semantic principle that prohibits such an expansion. (shrink)