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Vague Concepts (vague + concept)

Distribution by Scientific Domains
Humanities and Social Sciences80%

Selected Abstracts

Backbone Diversity Analysis in Catalyst Design

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009

Abstract We present a computer-based heuristic framework for designing libraries of homogeneous catalysts. In this approach, a set of given bidentate ligand-metal complexes is disassembled into key substructures ("building blocks"). These include metal atoms, ligating groups, backbone groups, and residue groups. The computer then rearranges these building blocks into a new library of virtual catalysts. We then tackle the practical problem of choosing a diverse subset of catalysts from this library for actual synthesis and testing. This is not trivial, since ,catalyst diversity' itself is a vague concept. Thus, we first define and quantify this diversity as the difference between key structural parameters (descriptors) of the catalysts, for the specific reaction at hand. Subsequently, we propose a method for choosing diverse sets of catalysts based on catalyst backbone selection, using weighted D-optimal design. The computer selects catalysts with different backbones, where the difference is measured as a distance in the descriptors space. We show that choosing such a D-optimal subset of backbones gives more diversity than a simple random sampling. The results are demonstrated experimentally in the nickel-catalysed hydrocyanation of 3-pentenenitrile to adiponitrile. Finally, the connection between backbone diversity and catalyst diversity, and the implications towards in silico catalysis design are discussed. [source]

Precise entities but irredeemably vague concepts?

DIALECTICA, Issue 3 2002
Enrique Romerales
Various arguments have recently been put forward to support the existence of vague or fuzzy objects. Nevertheless, the only possibly compelling argument would support, not the existence of vague objects, but indeterminately existing objects. I argue for the non-existence of any vague entities,either particulars or properties - in the mind-independent world. Even so, many philosophers have claimed that to reduce vagueness to semantics is of no avail, since linguistic vagueness betrays semantic incoherence and this is no less a problem than is ontological incoherence. After spelling out why there are fewer essentially vague concepts than usually thought. I claim that only the linguistic competence of the whole speaking community for each word can draw the sharp boundaries for its concept, even if these are unknowable in practice and still leave a precise range of indetermination. This could explain both the existence of boundaries and our non-removable ignorance of them, fulfilling the intuitions of the epistemic theory of vagueness with the supervaluationist's indeterminacy. [source]

A Wittgensteinian Solution to the Sorites

PHILOSOPHICAL INVESTIGATIONS, Issue 3 2010
Hanoch Ben-Yami
I develop a solution to the Sorites Paradox, according to which a concatenation of valid arguments need not itself be valid. I specify which chains of valid arguments are those that do not preserve validity: those that pass the vague boundary between cases where the relevant concept applies and cases where that concept does not apply. I also develop various criticisms of this solution and show why they fail; basically, they all involve a petitio at some stage. I criticise the conviction that if every short argument in a long concatenated argument is valid, so is the long argument: it is, I argue, the result of an unjustified generalisation from the case of arguments that do not employ vague concepts (as in mathematics) to arguments that do employ them. My approach is Wittgensteinian in its "leaving everything as it is," in its claiming that the "beginning" has been searched too far back (see paper's epigraph) and in its claim that the paradox was generated by a misapplication of a partial picture of the behaviour of arguments. I conclude my paper by comparing and contrasting my approach to the few precedents found in the vagueness literature and by answering a few additional objections that were raised there. [source]

Wittgenstein's Philosophical Grammar: A Neglected Discussion of Vagueness

PHILOSOPHICAL INVESTIGATIONS, Issue 2 2010
Nadine Faulkner
In this paper I explore a neglected discussion of vagueness put forward by Wittgenstein in his Philosophical Grammar (1932,34). In this work, unlike Philosophical Investigations (1953), Wittgenstein not only discusses the venerable Sorites paradox but provides a novel conception of vagueness using an analogy with coin tossing and converging intervals. As he sees it, the problematic picture of vagueness arises because we conflate aspects of the functioning of vague concepts with those of non-vague ones. Thus, while we accept that vague concepts have no sharp cut-off points (are boundaryless), we nevertheless retain the idea that we can progress towards the penumbra the way we progress towards the cut-off points of non-vague concepts. As a potential remedy, Wittgenstein's analogy with coin tossing and converging intervals replaces this picture and provides an understanding of the functioning of vague concepts in which no notion of a progression arises. [source]