Lieven Decock

I analyse conceptual change and conceptual engineering in the special case of colour concepts. The case raises the prospects of conceptual engineering because a precise standard for measuring the amelioration of the structure of concepts is available. On the other hand, the study highlights the problems with controlling conceptual engineering pointed out by Cappelen. I argue that in the case of conceptual change of colour concepts varying degrees of optimization, design and control are possible. I submit that this observation can be generalized to other classes of concepts. As a result, the scope of conceptual engineering is reduced considerably; conceptual engineering appears as a limit case of conceptual change.

Millions of human biological samples are stored worldwide for medical research or treatment purposes. These biospecimens are of enormous potential value to law enforcement as DNA profiles can be obtained from these samples. However, forensic use of such biospecimens raises a number of ethical questions. This article aims to explore ethical issues of using human bodily material in medical biobanks for crime investigation and prosecution purposes. Concerns about confidentiality, trust, autonomy and justice will be discussed. We explore how to balance these concerns against the importance of crime solving. Relevant case examples of forensic use of medical biobanks show that requests by law enforcement to access biobanks are handled in disparate ways. We identify some core ethical issues and conclude that further research on these issues is needed to provide ethical guidance.

Quine's views on indispensability arguments in mathematics are scrutinised. A weak indispensability argument is distinguished from a strong indispensability thesis. The weak argument is the combination of the criterion of ontological commitment, holism and a mild naturalism. It is used to refute nominalism. Quine's strong indispensability thesis claims that one should consider all and only the mathematical entities that are really indispensable. Quine has little support for this thesis. This is even clearer if one takes into account Maddy's critique of Quine's strong indispensability thesis. Maddy's critique does not refute Quine's weak indispensability argument. We are left with a weak and almost unassailable indispensability argument.

Color qualia inversion scenarios have played a key role in various philosophical debates. Most notably perhaps, they have figured in skeptical arguments for the fundamental unknowability of other persons’ color experiences. For these arguments to succeed, it must be assumed that a person's having inverted color qualia may go forever unnoticed. This assumption is now generally deemed to be implausible. The present paper defines a variant of color qualia inversion—termed ‘‘color qualia compression’’—and argues that the possibility of undetectable color qualia compression is immune to the objections that have been levelled against color qualia inversion arguments, and that color qualia compression scenarios support full-blown skepticism regarding other people's color experiences

It has seemed natural to model phenomena related to vagueness in terms of graded membership. However, so far no satisfactory answer has been given to the question of what graded membership is nor has any attempt been made to describe in detail a procedure for determining degrees of membership. We seek to remedy these lacunae by building on recent work on typicality and graded membership in cognitive science and combining some of the results obtained there with a version of the conceptual spaces framework

In recent years philosophers have been interested in the methodology of metaphysics. Most of these developments are related to formal work in logic or physics, often against the backdrop of the Carnap-Quine debate on ontology. Drawing on Quine’s later work, I argue that a psychological or cognitive perspective on metaphysical topics may be a valuable addition to contemporary metametaphysics. The method is illustrated by means of cognitive studies of the notions “identity,” “vagueness,” and “object” and is compared to other extant metametaphysical positions.

In two papers in the mid-seventies, Quine has discussed an ontological deba-cle, the reduction of ontology to an ontology of pure sets only. This debacle, which weakened Quine’s interest in ontology, is the natural outcome of on-tological relativity, or, more precisely, the proxy-function argument. It is ex-plained how Quine unavoidably came to this conclusion. Moreover, it is ar-gued that the result is even more damaging for Quine’s philosophy than has hitherto been assumed. It is shown that in addition to an ontological debacle, there is an ideological debacle, reducing the ideology (lexicon) of science to the ideology of set theory. The ideological debacle results from applying ex-tensional substitution of predicates within a scientific theory that is reinter-preted by means of proxy-functions to a theory with a set-theoretic ontology. Though Quine has recognized the possibility of an ideological debacle, his rebuttal is unconvincing. As a result, his tenet of extensionalism is under heavy pressure.

This paper traces the development of Quine's ontological ideas throughout his early logical work in the period before 1948. It shows that his ontological criterion critically depends on this work in logic. The use of quantifiers as logical primitives and the introduction of general variables in 1936, the search for adequate comprehension axioms, and problems with proper classes, all forced Quine to consider ontological questions. I also show that Quine's rejection of intensional entities goes back to his generalisation of Principia Mathematica in 1932

I want to analyse the Quine-Carnap discussion on analyticity with regard to logical, mathematical and set-theoretical statements. In recent years, the renewed interest in Carnap’s work has shed a new light on the analytic-synthetic debate. If one fully appreciates Carnap’s conventionalism, one sees that there was not a metaphysical debate on whether there is an analytic-synthetic distinction, but rather a controversy on the expedience of drawing such a distinction. However, on this view, there can be no longer a single analytic-synthetic distinction, because several kinds of statements could be regarded as analytic (L-determinate). L-equivalence between extra-logical linguistic predicates has already been heavily debated. The recent consensus states that Quine’s rejection of this analytic-synthetic is pragmatically grounded in his linguistic behaviorism. However, Carnap’s logical frameworks also contain other kinds of statements, and it is worthwhile to compare both Quine and Carnap’s grounds for considering these statements as analytic or not analytic. First, I will discuss logical statements. I will argue that Quine draws a very sharp distinction between first order logic and set theory, which should be regarded as a (pragmatic) analytic-synthetic distinction (as Quine admits in an interview, see Theoria, 40, 1994, p. 199). In fact, Quine’s major worry is whether identity statements are analytic. Second, I will discuss mathematical statements. In Carnap’s Foundations of Logic and Mathematics, it is clear that mathematical statements are analytic. For Quine, all mathematical statements are reducible to set-theoretical statements. Third, I discuss the analyticity of set-theoretical statements. For Quine, the membership predicate should be regarded as an interpreted extra-logical predicate. Quine’s work in set theory and his later philosophy of set theory naturally lead to the view that set-theoretical statements cannot be analytic. A major complication for the Quine-Carnap comparison is that Carnap has no elaborate reflections on set theory, while the influence of set theory on Quine’s views can hardly be underestimated. I conclude with some lessons for the contemporary debate on analyticity.

This paper considers Kamp and Partee's account of graded membership within a conceptual spaces framework and puts the account to the test in the domain of colors. Three experiments are reported that are meant to determine, on the one hand, the regions in color space where the typical instances of blue and green are located and, on the other hand, the degrees of blueness/greenness of various shades in the blue–green region as judged by human observers. From the locations of the typical blue and typical green regions in conjunction with Kamp and Partee's account follow degrees of blueness/greenness for the color shades we are interested in. These predicted degrees are compared with the judged degrees, as obtained in the experiments. The results of the comparison support the account of graded membership at issue.

In a famous critique, Goodman dismissed similarity as a slippery and both philosophically and scientifically useless notion. We revisit his critique in the light of important recent work on similarity in psychology and cognitive science. Specifically, we use Tversky’s influential set-theoretic account of similarity as well as Gärdenfors’s more recent resuscitation of the geometrical account to show that, while Goodman’s critique contained valuable insights, it does not warrant a dismissal of similarity

Reflectance physicalism only provides a partial picture of the ontology of color. Byrne & Hilbert’ account is unsatisfactory because the replacement of reflectance functions by productance functions is ad hoc, unclear, and only leads to new problems. Furthermore, the effects of color contrast and differences in illumination are not really taken seriously: Too many “real” colors are tacitly dismissed as illusory, and this for arbitrary reasons. We claim that there cannot be an all-embracing ontology for color.