This chapter contains sections titled: From the Synoptic View to the Album “I don't know my way about” The Problem of Grammar Essential Complexity The Practice of Language Hyper ‐ complexity.

Wayne Martin’s Theories of Judgment marks a significant advance in the philosophical analysis of judgment. He understands that the domain of judgment is so large that it allows only a selective treatment. We can expand Martin’s insight by acknowledging that this domain is, in fact, hypercomplex and therefore unsurveyable in Wittgenstein’s sense. Martin’s treatment of judgments can, however, be extended in a number of directions. Of particular importance is it to understand the linguistic aspect of theoretical judgments, the challenges to (...) the synthetic conception of judgment constituted not only by existential, but also by impersonal and negative judgments, and the exploration of the links between the notions of judgment and truth. (shrink)

In Part III of his Remarks on the Foundations of Mathematics Wittgenstein deals with what he calls the surveyability of proofs. By this he means that mathematical proofs can be reproduced with certainty and in the manner in which we reproduce pictures. There are remarkable similarities between Wittgenstein's view of proofs and Hilbert's, but Wittgenstein, unlike Hilbert, uses his view mainly in critical intent. He tries to undermine foundational systems in mathematics, like logicist or set theoretic ones, by stressing the (...) unsurveyability of the proof-patterns occurring in them. Wittgenstein presents two main arguments against foundational endeavours of this sort. First, he shows that there are problems with the criteria of identity for the unsurveyable proof-patterns, and second, he points out that by making these patterns surveyable, we rely on concepts and procedures which go beyond the foundational frameworks. When we take these concepts and procedures seriously, mathematics does not appear as a uniform system, but as a mixture of different techniques. (shrink)

The original proof of the four-color theorem by Appel and Haken sparked a controversy when Tymoczko used it to argue that the justification provided by unsurveyable proofs carried out by computers cannot be a priori. It also created a lingering impression to the effect that such proofs depend heavily for their soundness on large amounts of computation-intensive custom-built software. Contra Tymoczko, we argue that the justification provided by certain computerized mathematical proofs is not fundamentally different from that provided by surveyable (...) proofs, and can be sensibly regarded as a priori. We also show that the aforementioned impression is mistaken because it fails to distinguish between proof search (the context of discovery) and proof checking (the context of justification). By using mechanized proof assistants capable of producing certificates that can be independently checked, it is possible to carry out complex proofs without the need to trust arbitrary custom-written code. We only need to trust one fixed, small, and simple piece of software: the proof checker. This is not only possible in principle, but is in fact becoming a viable methodology for performing complicated mathematical reasoning. This is evinced by a new proof of the four-color theorem that appeared in 2005, and which was developed and checked in its entirety by a mechanical proof system. (shrink)

Several high-profile mathematical problems have been solved in recent decades by computer-assisted proofs. Some philosophers have argued that such proofs are a posteriori on the grounds that some such proofs are unsurveyable; that our warrant for accepting these proofs involves empirical claims about the reliability of computers; that there might be errors in the computer or program executing the proof; and that appeal to computer introduces into a proof an experimental element. I argue that none of these arguments withstands scrutiny, (...) and so there is no reason to believe that computer-assisted proofs are not a priori. Thanks are due to Michael Levin, David Corfield, and an anonymous referee for Philosophia Mathematica for their helpful comments. Earlier versions of this paper were presented at the Hofstra University Department of Mathematics colloquium series, and at the 2005 New Jersey Regional Philosophical Association; I am grateful to both audiences for their comments. CiteULike Connotea Del.icio.us What's this? (shrink)

In various contexts, it is thought to be important that we reason together. For instance, an attractive conception of democracy requires that citizens reach lawmaking decisions by reasoning with one another. Reasoning requires that reasoners survey the considerations that they take to be reasons, proceed by a coherent train of thought, and reach conclusions freely. De facto reliance on experts threatens the possibility of collective reasoning by making some reasons collectively unsurveyable, raising questions about the coherence of the resulting train (...) of thought. De jure reliance on experts threatens the possibility of collective reasoning by seeming to make some conclusions irreversible. The paper argues that collective reasoning that relies on experts would nonetheless be possible if the unsurveyable reasons "mesh," if the expert considerations are at least in principle publicly recoverable, and if de jure authority of expert decision is always subject to appeal. (shrink)

Saul Kripke has made fundamental contributions to a variety of areas of logic, and his name is attached to a corresponding variety of objects and results. 1 For philosophers, by far the most important examples are ‘Kripke models’, which have been adopted as the standard type of models for modal and related non-classical logics. What follows is an elementary introduction to Kripke’s contributions in this area, intended to prepare the reader to tackle more formal treatments elsewhere.2 2. WHAT IS A (...) MODEL THEORY? Traditionally, a statement is regarded as logically valid if it is an instance of a logically valid form, where a form is regarded as logically valid if every instance is true. In modern logic, forms are represented by formulas involving letters and special symbols, and logicians seek therefore to define a notion of model and a notion of a formula’s truth in a model in such a way that every instance of a form will be true if and only if a formula representing that form is true in every model. Thus the unsurveyably vast range of instances can be replaced for purposes of logical evaluation by the range of models, which may be more tractable theoretically and perhaps practically. Consideration of the familiar case of classical sentential logic should make these ideas clear. Here a formula, say (p & q) ∨ ¬p ∨ ¬q, will be valid if for all statements P.. (shrink)

The task of this paper is to exhibit Wittgenstein’s method of perspicuous presentation as aiming at a distinctive kind of self-knowledge. Three influential readings of Wittgenstein’s concept of perspicuous presentation – Hacker’s, Baker’s and Sluga’s – are examined. All of them present what Wittgenstein calls the “unsurveyablity of our grammar” as a result of the “complexity” of our language. Contrary to this, a fundamental difference between matter-of-factual complexity and the unsurveyability of grammar is pointed out. What perspicuous presentations are (...) designed to deal with, isn’t, accordingly, occasioned by the complexity of our language but by an unnoticed assimilation of our own activities as speaking beings to matter-of-factual affairs. In response to this, perspicuous presentations help us to fully appropriate our activities as speakers in virtue of achieving a transparent understanding of the use of “our words”. It thus provides us with a distinctive kind of grammatical self-knowledge. (shrink)

Appropriated as an icon by an astonishingly diverse spectrum of people, Friedrich Wilhelm Nietzsche has been the subject of countless volumes of literature. Until now, though, there has been no in-depth study devoted specifically to Nietzsches thoughts and impact on architecture. In the essays comprising Nietzsche and An Architecture of Our Minds, thirteen eminent scholars from a wide variety of disciplines--including art history, architecture and architecture theory, literature, philosophy, and city planning--address his far-reaching notion of an architecture commensurate with the (...) modern mind. They assess the relationship of Nietzschean philosophy to art and architecture, elucidate frequent misunderstandings, and determine patterns of influence, illuminating an unsurveyed aspect of the philosophy of one of the most profound thinkers of the modern age. (shrink)

As far as logic is concerned, the conclusion of Michael Dummett's manifestability argument is that intuitionistic logic, as first developed by Heyting, satisfies the semantic requirements of antirealism. The argument may be roughly sketched as follows: since we cannot manifest a grasp of possibly justification-transcendent truth conditions, we must countenance conditions which are such that, at least in principle and by the very nature of the case, we are able to recognize that they are satisfied whenever they are. Intuitionistic logic (...) satisfies the semantic requirement that we should either eschew the notion of truth altogether and replace it by provability in principle, or constrain it by provability in principle (Dummett [1973] 1978). (Handout: 1-5). Some philosophers have argued that the traditional antirealist desideratum of decidability in principle is too weak, so that semantic antirealism properly construed must be committed to effective decidability. As such, it either leads to strict finitism (Wright [1982] 1993) [Handout: 6] or to a much stronger kind of logical revisionism than the one considered by intuitionists (whether or not they accept the manifestability argument): substructural logics, and in particular linear logics, rather than intuitionistic logic, satisfy the semantic requirements of strict antirealism (Dubucs and Marion 2004) [Handout: 8-9]. I shall develop two different kinds of replies. The first is concerned with the notion of meaning per se and looks to strict finitism directly, although not on the ground that it would provide a correct way of dealing with Soritic-type paradoxes (the original and primary focus of discussion in Wright [1982] 1993). The second is concerned with the justification of structural and logical rules in a natural deduction system à la Gentzen. It will deal in particular with the criticism of the structural rules of Weakening and Contraction [Handout: 10 and 11]. The first kind of reply, which Dummett has partially taken into consideration, is that if we jettison the effectively vs. in principle distinction, as applied to manifestability-type arguments, we end up with an unsatisfactory explanation of how the meaning of statements covering the practically unsurveyable or pro tempora undecided cases is fixed. The idea is that if we have a method which may be used over some small range, we have determined a way of applying the method everywhere in principle and that this is enough as far as fixing meaning is concerned. Decidability in principle is just what we need with respect to manifestation of grasp of meaning. In this perspective, antirealism shouldn't be strict and manifestability-type arguments need not be applied as far as the strict finitist would want to [Handout: 7]. It follows that there is no reason to think that practical feasibility should be built in assertibility conditions and proofs be construed dynamically as acts in the strict antirealist's acception of that term [Handout: 8]. I shall then look at one radical antirealist principle disqualifying structural rules, namely Token Preservation, arguing against Bonnay and Cozic's criticisms of Dubucs and Marion (Bonnay and Cozic 3 2007) that some conceptual support may be provided for Token Preservation, which doesn't rely on a causal misreading of the turnstile [Handout: 13, 14]. I shall then assess the merits and limits of radical antirealism and the logic of feasible proofs with respect to the original Dummettian argument in favour of semantic antirealism (provided it has indeed revisionist implications for logic), whether the radical antirealist merely stipulates what human feasibility amounts to, or dispenses with structural rules in order to argue in favour of a curb on the epistemic idealizations they unwarrantedly embed. It will be noted here that there is a great difference, conceptually speaking, between the rejection of classical logic via the curbing of the epistemic idealizations embedded in structural rules, and the rejection of classical logic via the criticism of the introduction and elimination rules which fix the meaning of the classical constants. The kind of logical revisionism envisaged by intuitionists from Heyting on is in many respects stronger than the one envisaged by advocates of linear logic, should they ground their arguments on an endorsement of strict antirealism. The crucial case of excluded middle is telling. Because of the splitting of the constants in linear logic (Handout: 12], two distinct laws of excluded middle may be formulated (Handout: 15), but the traditional arguments of Brouwer and Heyting against the classical law yield a stronger revision than the substructural revision with its admission of these two (very) weak versions of the law. (Project: a clearer conception is needed of how the introduction and elimination rules for the logical connectives in the intuitionistic calculus depend on the structural rules which the radical antirealist wishes to reject.). (shrink)

Saul Kripke’s analysis of the concept of the natural numbers that we are taught in school yields a novel and axiomatically economical way of representing arithmetic in standard set theory—one that helps to answer Benacerraf’s objection from extraneous content as well as Wittgenstein’s objection from unsurveyability. After describing Kripke’s proposal in some detail, we examine it in the light of work by Quine, Steiner, Parsons, Boolos and Burgess. Although the primary aim of this paper is to present and explicate (...) Kripke’s view, we conclude by discussing some of the issues that are faced by Kripke’s proposal, so that the reader can get a sense of the geography of these issues. (shrink)

The philosolphy of strict finitism is a research programme containing developmental theory and mathematics as its main branches. The first branch is concerned with the ontogenetic and historicaldevelopment of various concepts of infinity. The frame work is Jean Piaget’s genetic epistemology. Based upon these develop mental studies, the mathematical branch introduces a new concept of infinity into mathematics. Cantor propagated the actual infinite, Brouwer and the constructivists the potential infinite. Still more radical is strict finitism, favoring the natural infinite, i.e. (...) the phenomena of the unsurveyable, unfeasible, unreachable. There exist by this time strict finitistic reconstructions for arithmetic, geometry, calculus, and even for infinitistic set theory. (shrink)

Wayne Martin 's Theories of Judgment marks a significant advance in the philosophical analysis of judgment. He understands that the domain of judgment is so large that it allows only a selective treatment. We can expand Martin 's insight by acknowledging that this domain is, in fact, hypercomplex and therefore unsurveyable in Wittgenstein's sense. Martin 's treatment of judgments can, however, be extended in a number of directions. Of particular importance is it to understand the linguistic aspect of theoretical judgments, (...) the challenges to the synthetic conception of judgment constituted not only by existential, but also by impersonal and negative judgments, and the exploration of the links between the notions of judgment and truth. (shrink)