De George's understanding of theology is limited to one of five commonly recognized models of theology, the orthodox model. This model is vulnerable to De George's criticisms. When religious ethics operates out of the revisionist model of theology, however, his criticisms lose their sting. Revisionist religious ethics, moreover, can make a fruitful contribution to business ethics. Such a religious ethic acknowledges the embodiment dimension of business activities, it complements philosophical analysis with the practice of moral discernment, and it recognizes irony (...) as an active component in decision-making. (shrink)

Hrushovski originated the study of “flat” stable structures in constructing a new strongly minimal set and a stable 0-categorical pseudoplane. We exhibit a set of axioms which for collections of finite structure with dimension function δ give rise to stable generic models. In addition to the Hrushovski examples, this formalization includes Baldwin's almost strongly minimal non-Desarguesian projective plane and several others. We develop the new case where finite sets may have infinite closures with respect to the dimension function δ. In (...) particular, the generic structure need not be ω-saturated and so the argument for stability is significantly more complicated. We further show that these structures are “flat” and do not interpret a group. (shrink)

Major shifts in the field of model theory in the twentieth century have seen the development of new tools, methods, and motivations for mathematicians and philosophers. In this book, John T. Baldwin places the revolution in its historical context from the ancient Greeks to the last century, argues for local rather than global foundations for mathematics, and provides philosophical viewpoints on the importance of modern model theory for both understanding and undertaking mathematical practice. The volume also addresses the impact (...) of model theory on contemporary algebraic geometry, number theory, combinatorics, and differential equations. This comprehensive and detailed book will interest logicians and mathematicians as well as those working on the history and philosophy of mathematics. (shrink)

We give a general account of the goals of axiomatization, introducing a variant on Detlefsen’s notion of ‘complete descriptive axiomatization’. We describe how distinctions between the Greek and modern view of number, magnitude, and proportion impact the interpretation of Hilbert’s axiomatization of geometry. We argue, as did Hilbert, that Euclid’s propositions concerning polygons, area, and similar triangles are derivable from Hilbert’s first-order axioms. We argue that Hilbert’s axioms including continuity show much more than the geometrical propositions of Euclid’s theorems and (...) thus are an immodest complete descriptive axiomatization of that subject. (shrink)

We explore Shelah's model‐theoretic dividing line methodology. In particular, we discuss how problems in model theory motivated new techniques in model theory, for example classifying theories by their potential (consistently with Zermelo–Fraenkel set theory with the axiom of choice (ZFC)) spectrum of cardinals in which there is a universal model. Two other examples are the study (with Malliaris) of the Keisler order leading to a new ZFC result on cardinal invariants and attempts to clarify the “main gap” by reducing the (...) dependence of certain versions on (highly independent) cardinal arithmetic. (shrink)

In this paper we study abstract elementary classes of modules. We give several characterizations of when the class of modules A with is abstract elementary class with respect to the notion that M1 is a strong submodel M2 if the quotient remains in the given class.

We study when classes can have the disjoint amalgamation property for a proper initial segment of cardinals. Theorem A For every natural number k, there is a class $K_k $ defined by a sentence in $L_{\omega 1.\omega } $ that has no models of cardinality greater than $ \supset _{k - 1} $ , but $K_k $ has the disjoint amalgamation property on models of cardinality less than or equal to $\mathfrak{N}_{k - 3} $ and has models of cardinality $\mathfrak{N}_{k (...) - 1} $ . More strongly, we can have disjoint amalgamation up to $\mathfrak{N}_\alpha $ for α > ω, but have a bound on size of models. Theorem B For every countable ordinal a, there is a class $K_\alpha $ defined by a sentence in $L_{\omega 1.\omega } $ that has no models of cardinality greater than $ \supset _{\omega 1} $ , but K does have the disjoint amalgamation property on models of cardinality less than or equal to $\mathfrak{N}_\alpha $ . Finally we show that we can extend the $\mathfrak{N}_\alpha $ to $ \supset _\alpha $ in the second theorem consistently with ZFC and while having $\mathfrak{N}_i \ll \supset _i $ for 0 > i < α. Similar results hold for arbitrary ordinals α with |α|= K and $L_{k + ,\omega } $. (shrink)

We prove two results on the stability spectrum for Lω1,ω. Here [Formula: see text] denotes an appropriate notion of Stone space of m-types over M. Theorem for unstable case: Suppose that for some positive integer m and for every α μ, K is not i-stable in μ. These results provide a new kind of sufficient condition for the unstable case and shed some light on the spectrum of strictly stable theories in this context. The methods avoid the use of compactness (...) in the theory under study. In this paper, we expound the construction of tree indiscernibles for sentences of Lω1,ω. Further we provide some context for a number of variants on the Ehrenfeucht–Mostowski construction. (shrink)

In Part I of this paper we argued that the first-order systems HP5 and EG are modest complete descriptive axiomatization of most of Euclidean geometry. In this paper we discuss two further modest complete descriptive axiomatizations: Tarksi’s for Cartesian geometry and new systems for adding $$\pi$$. In contrast we find Hilbert’s full second-order system immodest for geometrical purposes but appropriate as a foundation for mathematical analysis.

We provide a general framework for studying the expansion of strongly minimal sets by adding additional relations in the style of Hrushovski. We introduce a notion of separation of quantifiers which is a condition on the class of expansions of finitely generated models for the expanded theory to have a countable ω-saturated model. We apply these results to construct for each sufficiently fast growing finite-to-one function μ from 'primitive extensions' to the natural numbers a theory T μ of an expansion (...) of an algebraically closed field which has Morley rank 2. Finally, we show that if μ is not finite-to-one the theory may not be ω-stable. (shrink)

We introduce the notion T does not omit obstructions. If a stable theory does not admit obstructions then it does not have the finite cover property (nfcp). For any theory T, form a new theory by adding a new unary function symbol and axioms asserting it is an automorphism. The main result of the paper asserts the following: If T is a stable theory, T does not admit obstructions if and only if has a model companion. The proof involves some (...) interesting new consequences of the nfcp. (shrink)

The projective plane of Baldwin 695) is model complete in a language with additional constant symbols. The infinite rank bicolored field of Poizat 1339) is not model complete. The finite rank bicolored fields of Baldwin and Holland 371; Notre Dame J. Formal Logic , to appear) are model complete. More generally, the finite rank expansions of a strongly minimal set obtained by adding a ‘random’ unary predicate are almost strongly minimal and model complete provided the strongly minimal set is ‘well-behaved’ (...) and admits ‘exactly rank k formulas’. The last notion is a geometric condition on strongly minimal sets formalized in this paper. (shrink)

CHAPTER 1 Combinatorial Geometries and Infinitary Logics In this chapter we introduce two of the key concepts that are used throughout the text. ...

Studies in the neurobiological underpinnings of social information processing bypsychologists, neurobiologists, psychiatrists, radiologists, and neurologists, using methods thatrange from brain imaging techniques to comparative analyses.

We use κ-free but not Whitehead Abelian groups to constructElementary Classes (AEC) which satisfy the amalgamation property but fail various conditions on the locality of Galois-types. We introduce the notion that an AEC admits intersections. We conclude that for AEC which admit intersections, the amalgamation property can have no positive effect on locality: there is a transformation of AEC's which preserves non-locality but takes any AEC which admits intersections to one with amalgamation. More specifically we have: Theorem 5.3. There is (...) an AEC with amalgamation which is not (N₀, N₁)-tame but is 2(N0, ∞)-tame; Theorem 3.3. It is consistent with ZFC that there is an AEC with amalgamation which is not (≤ N₂, ≤ N₂)-compact. (shrink)

I describe a problem about the relations among symmetries, laws and measurable quantities. I explain why several ways of trying to solve it will not work, and I sketch a solution that might work. I discuss this problem in the context of Newtonian theories, but it also arises for many other physical theories. The problem is that there are two ways of defining the space-time symmetries of a physical theory: as its dynamical symmetries or as its empirical symmetries. The two (...) definitions are not equivalent, yet they pick out the same extension. This coincidence cries out for explanation, and it is not clear what the explanation could be. The Puzzle: Symmetries, Measurability and Invariance 1.1 The symmetries and the measurable quantities of Newtonian mechanics 1.2 The puzzle Two Easy Answers Another Unsuccessful Solution: Appeal to Geometrical Symmetries Locating the Puzzle The Relation between Laws and Measurability A Possible Solution CiteULike Connotea Del.icio.us What's this? (shrink)

Let $\mathbf{I}(\mu,K)$ denote the number of nonisomorphic models of power $\mu$ and $\mathbf{IE}(\mu,K)$ the number of nonmutually embeddable models. We define in this paper the notion of a diverse class and use it to prove a number of results. The major result is Theorem B: For any diverse class $K$ and $\mu$ greater than the cardinality of the language of $K$, $\mathbf{IE}(\mu,K) \geq \min(2^\mu,\beth_2).$ From it we deduce both an old result of Shelah, Theorem C: If $T$ is countable and (...) $\lambda_0 > \aleph_0$ then for every $\mu > \aleph_0,\mathbf{IE}(\mu,T) \geq \min(2^\mu,\beth_2)$, and an extension of that result to uncountable languages, Theorem D: If $|T| < 2^\omega,\lambda_0 > |T|$, and $|D(T)| = |T|$ then for $\mu > |T|$, $\mathbf{IE}(\mu,T) \geq \min(2^\mu,\beth_2).$. (shrink)

$\underline{\text{Saturation is} (\mu, \kappa)-\text{transferable in} T}$ if and only if there is an expansion T 1 of T with ∣ T 1 ∣ = ∣ T ∣ such that if M is a μ-saturated model of T 1 and ∣ M ∣ ≥ κ then the reduct M ∣ L(T) is κ-saturated. We characterize theories which are superstable without f.c.p., or without f.c.p. as, respectively those where saturation is (ℵ 0 , λ)- transferable or (κ (T), λ)-transferable for all λ. (...) Further if for some $\mu \geq \mid T \mid, 2^\mu > \mu^+$ , stability is equivalent to for all μ ≥ ∣ T ∣, saturation is (μ, 2 μ )- transferable. (shrink)

The law-governed world-picture -- A remarkable idea about the way the universe is cosmos and compulsion -- The laws as the cosmic order : the best-system approach -- The three ways : no-laws, non-governing-laws, governing-laws -- Work that laws do in science -- An important difference between the laws of nature and the cosmic order -- The picture in four theses -- The strategy of this book -- The meta-theoretic conception of laws -- The measurability approach to laws -- What (...) comes where -- In defense of some received views -- Some assumptions that will be in play -- The laws are propositions -- The laws are true -- The logically contingent consequences of the laws are laws themselves -- At least some laws are metaphysically contingent -- The meta-theoretic conception of laws -- Laws of nature, laws of science, laws of theories -- The first-order conception versus the meta-theoretic conception -- What is a law of nature? -- Some examples of meta-theoretic accounts -- The virtues of the meta-theoretic conception -- Weighing the virtues and shortcomings of the meta-theoretic conception -- An epistemological argument for the meta-theoretic conception of laws -- The discoverability thesis, the governing thesis, and the first-order conception -- The main argument -- The objection from bad company -- The objection from inference to the best explanation -- The objection from bayesianism -- The objection from contextualist epistemology -- The objection from the threat of inductive skepticism -- Laws, governing, and counterfactuals -- Where we are now -- What would things have to be like in order for the laws of nature to govern the universe? -- Lawhood, inevitability, counterfactuals -- What is it for a proposition to be inevitably true? -- What is it for a whole class of propositions to be inevitably true? -- What is it for lawhood to confer inevitability? -- NP and supporting counterfactuals -- The worry about context-variability -- A solution and a look ahead -- When would the laws have been different? -- Where we are now -- The God cases -- Other counterexamples to NP -- A moral-theoretic counterexample to NP -- Scientific contexts and non-scientific contexts -- Scientific God cases? -- Lewisian non-backtracking counterexamples -- Where things stand now -- How could science show that the laws govern? -- Why the law-governed world-picture must include the science-says-so thesis -- What is extra-scientific? -- How can the science-says-so thesis be true? -- NP as a consequence of the presuppositions in any scientific context -- Np as true in all possible scientific contexts -- But how could it be so? -- Attack of the actual-factualists -- Measurement and counterfactuals -- Where we are now -- Measurements, reliability, counterfactuals -- A general principle that captures the relation between measurement and counterfactuals -- What we can learn about lawhood from what we have learned about the counterfactual commitments of science -- A first-order account of laws or a meta-theoretic account of laws? -- What methods are presupposed to be legitimate measurement procedures? -- Why we must adopt a meta-theoretic account of laws -- What lawhood is -- Where we are now -- The measurability account of laws -- Brief review of the case for the mal -- A note about hedged laws -- How plausible is the mal? -- What if we don't care about the law-governed world-picture? -- Newton's God and Laplace's demon -- Beyond humean and non-humean -- Two views of laws -- Humean supervenience and the meta-theoretic conception -- Alleged counterexamples to humean supervenience -- Governing and non-trivial necessity -- How the mal lets us have it all -- Humeanism? non-humeanism? -- What is the significance of the idea of the law-governed universe? -- Where in the world are the laws of nature? -- Appendix: The mal in action : a few examples -- Of scientific theories and their laws -- Newton's theory as a paradigm example -- Classical special-force laws -- Geometrical optics and one of its laws -- Local deterministic field theories. (shrink)

This paper contains portions of Baldwin’s talk at the Set Theory and Model Theory Conference and a detailed proof that in a suitable extension of ZFC, there is a complete sentence of \ that has maximal models in cardinals cofinal in the first measurable cardinal and, of course, never again.

A varietyV satisfies a strong Malcev condition ∃f1,…, ∃fnθ where θ is a conjunction of equations in the function variablesf1, …,fnand the individual variablesx1, …,xm, if there are polynomial symbolsp1, …,pnin the language ofVsuch that ∀x1, …,xmθ is a law ofV. Thus a strong Malcev condition involves restricted second order quantification of a strange sort. The quantification is restricted to functions which are “polynomially definable”. This notion was introduced by Malcev [6] who used it to describe those varieties all of (...) whose members have permutable congruence relations. The general formal definition of Malcev conditions is due to Grätzer [1]. Since then and especially since Jónsson's [3] characterization of varieties with distributive congruences there has been extensive study of strong Malcev conditions and the related concepts: Malcev conditions and weak Malcev conditions.In [9], Taylor gives necessary and sufficient semantic conditions for a class of varieties to be defined by a Malcev condition. A key to the proof is the translation of the restricted second order concepts into first order concepts in a certain many sorted language. In this paper we show that, given this translation, Taylor's theorem is an easy consequence of a result of Tarski [8] and the standard preservation theorems of first order logic. (shrink)

We give a complete and elementary proof of the following upward categoricity theorem: let be a local abstract elementary class with amalgamation and joint embedding, arbitrarily large models, and countable Löwenheim–Skolem number. If is categorical in 1 then is categorical in every uncountable cardinal. In particular, this provides a new proof of the upward part of Morley’s theorem in first order logic without any use of prime models or heavy stability theoretic machinery.

The most important voices concerning the changes now occurring in Central and Eastem Europe are those that come from within, for those voices are informed not only by indifferent data and objective reports, but by personal hopes, fears, desires and needs. Without careful consideration of what such voices say, judgment can only be sterile. Furthermore, policy decisions made without the benefit of the intemal perspective are likely to be flawed, and ineffectual. Policies won’t work if they do not take into (...) account the point of view of those who are supposed to be affected by them. There nevertheless remains an important role for outsiders to play in the discussion of the impact of political change on the future of philosophical thought, especially if the outside perspective can serve as a test of the internal view. (shrink)

Both physicists and philosophers claim that quantum mechanics reduces to classical mechanics as 0, that classical mechanics is a limiting case of quantum mechanics. If so, several formal and non-formal conditions must be satisfied. These conditions are satisfied in a reduction using the Wigner transformation to map quantum mechanics onto the classical phase plane. This reduction does not, however, assist in providing an adequate metaphysical interpretation of quantum theory.

I propose understanding CP-law statements as statements that assert the existence of vague statistical laws, not by fully specifying the contents of those laws, but by picking them out via a description that is both self-referential and self-locating. I argue that this proposal validates many common assumptions about CP-laws and correctly classifies many examples of putative CP-laws. It does this while avoiding the most serious worries that motivate some philosophers to be skeptical of CP-laws, namely the worry that they lack (...) non-trivial truth conditions and that it is impossible for empirical evidence to disconfirm them. (shrink)

We propose a criterion to regard a property of a theory (in first or second order logic) as virtuous: the property must have significant mathematical consequences for the theory (or its models). We then rehearse results of Ajtai, Marek, Magidor, H. Friedman and Solovay to argue that for second order logic, ‘categoricity’ has little virtue. For first order logic, categoricity is trivial; but ‘categoricity in power’ has enormous structural consequences for any of the theories satisfying it. The stability hierarchy extends (...) this virtue to other complete theories. The interaction of model theory and traditional mathematics is examined by considering the views of such as Bourbaki, Hrushovski, Kazhdan, and Shelah to flesh out the argument that the main impact of formal methods on mathematics is using formal definability to obtain results in ‘mainstream’ mathematics. Moreover, these methods (e.g., the stability hierarchy) provide an organization for much mathematics which gives specific content to dreams of Bourbaki about the architecture of mathematics. (shrink)

We describe techniques for constructing models of size continuum inωsteps by simultaneously building a perfect set of enmeshed countable Henkin sets. Such models have perfect, asymptotically similar subsets. We survey applications involving Borel models, atomic models, two-cardinal transfers and models respecting various closure relations.

We show that K-generic projective planes have Morley rank either two or infinity. We also show give a direct argument that such planes are not Desarguesian.

First published in 1969, this volume presents a survey of the contemporary national education system in Latin American countries. Laurence Gale describes the uneven provision of schools for different sections of the community and the problems which arise with the racial, cultural and geographical difficulties. He examines the main features in education throughout Latin America, areas of co-operation and agreement and differences of policy and provision.

I argue that the most promising approach to understanding J.J. Gibson's "affordances" takes affordances themselves as ontological primitives, instead of treating them as dispositional properties of more primitive things, events, surfaces, or substances. These latter are best treated as coalescences of affordances present in the environment (or "coalescences of use-potential," as in Sanders (1994) and Hilditch (1995)). On this view, even the ecological approach's stress on the complementary organism/environment pair is seen as expressing a particular affordance relation between the world (...) and the analyst. That the world is parsed in any way among events and objects, perceivers and worlds, etc., reflects equally features of certain real or possible perspectives on the world and features of the world itself. In section 1, I begin by contending that, contrary to the apparent expectations of some in the field, the bare existence of affordances is surely quite uncontroversial. In section 2, I argue that the most reasonable approach to foundational ontology is a relativistic one. In section 3, I address the claim that affordances must be ontologically complemented by effectivities for the sake of completeness, and I shall argue against that claim on grounds that I take to reflect some of Gibson's most important insights. This work will help to clarify the way affordances are to be used in the fourth and final section, where I argue that ontological work, even within special sciences, should not be merely "regional," and that the most attractive general approach to ontological questions is one that is based on affordances, rather than upon things, events, surfaces, and the like. (shrink)

This paper ties together much of the model theory of the last 50 years. Shelah's attempts to generalize the Morley theorem beyond first order logic led to the notion of excellence, which is a key to the structure theory of uncountable models. The notion of Abstract Elementary Class arose naturally in attempting to prove the categoricity theorem for L ω 1 ,ω (Q). More recently, Zilber has attempted to identify canonical mathematical structures as those whose theory (in an appropriate logic) (...) is categorical in all powers. Zilber's trichotomy conjecture for first order categorical structures was refuted by Hrushovski, by the introducion of a special kind of Abstract Elementary Class. Zilber uses a powerful and essentailly infinitary variant on these techniques to investigate complex exponentiation. This not only demonstrates the relevance of Shelah's model theoretic investigations to mainstream mathematics but produces new results and conjectures in algebraic geometry. (shrink)

John Taurek has argued that, where choices must be made between alternatives that affect different numbers of people, the numbers are not, by themselves, morally relevant. This is because we "must" take "losses-to" the persons into account (and these don't sum), but "must not" consider "losses-of" persons (because we must not treat persons like objects). I argue that the numbers are always ethically relevant, and that they may sometimes be the decisive consideration.