Online research in philosophy

Even if the literature on the effects of pupil composition has been extensive, no clear consensus has been reached concerning the significance and magnitude of this effect. The first objective of this article is to estimate the magnitude of the school composition effect in primary schools (6th grade) in French-speaking Belgium. Different indicators of school composition are used: academic, socio-cultural, 'language' and sex composition. Except for sex composition, the results show that the school composition effect explains significant amount of between schools variance even after controlling for pupils' initial performance, socio-cultural background, and non-cognitive dispositions. The second objective is to examine covariance between school composition and several organisational variables and their joint effect on school performance. The second set of analyses is intended to question the conceptual nature of the school composition effect, establishing whether it is direct or indirect.

Orthodoxy says that the thesis that composition is identity (CAI) entails universalism: the claim that any collection of entities has a sum. If this is true it counts in favour of CAI, since a thesis about the nature of composition that settles the otherwise intractable special composition question (SCQ) is desirable. But I argue that it is false: CAI is compatible with the many forms of restricted composition, and SCQ is no easier to answer given CAI than otherwise. Furthermore, in seeing why this is the case we reveal an objection to CAI: that it allows for the facts concerning what there is to be settled whilst leaving open the question about what is identical to what.

The question of the constituting nature of colour is largely open. The old dispute between colour objectivism and colour subjectivism is still relevant. The former has defended itself against accusations of not being able to explain colour structures, while the latter view has received criticism for not being able to provide a plausible theory of the location of colours. By weakening the notion of physical categories, making some of them perceiver-depended, colour objectivists have managed to overcome at least some of the previous accusations. However, the arguments based on Crane's and Piantanida's findings of the existence of binary colours like greenish-red and yellowish-blue, indicate the inadequacy of colour objectivism. Consequently, we have colours but our theories of them are false.

Our various theories and conceptions of colours are influenced by the two main perspectives which we have on them. On the one hand, colours are directly given to us, in our conscious perceptual experiences, as features of objects in our environment. As part of these experiences, the colours instantiated by the objects are presented as having certain qualitative and certain categorial properties. Among the sensorily presented qualitative features of colours are, first of all, their various internal similarities and differences. Thus, two colours may be experienced as being closer to each other in their hue, their saturation or their brightness than a third colour. Their qualitative features also include the property of being unique (or elemental) or, alternatively, the property of being binary (or compound). While unique shades of hue are experienced as not involving any other colour hues, binary shades of hue are experienced as being qualitatively composed out of the former. The property of being instantiated independently of our particular experiences and the property of being instantiated by some actually existing objects are some of the categorical features1, which we non-sensorily experience colour instances as having. That is, the colours which we perceive are given to us as mind-independent properties of real objects. Another relevant aspect - though probably more controversial - may perhaps be that we experience colour instances as determining our perceptions of them. The idea is that, while seeing the colours of objects, we are aware of the fact that, if the colours would have been different, our experiences of them would have been correspondingly different as well (cf. Author (2010a)). The categorial features are the same for all perceived colours instances that we perceive. The qualitative features, of course, differ relative to which colour we experience. The non-sensory presentation of the categorical features of colour instances and the sensory presentation of the qualitative features of the colours involved contribute to the subjective character of the relevant colour experiences — to what they are subjectively like..

“Under what circumstances do things add up to or compose something?” This is what Peter van Inwagen (1990, p. 31) calls the Special Composition Question. Everyone, it seems, has a different answer. Van Inwagen’s, famously, is “when the activities of those things constitute a life”. Other people — nihilists about composition — say “never!” Other people — universalists about composition — say “always!”. Yet other people — brutalists about composition — say that there is no answer.

David Lewis (1986) criticizes moderate views of composition on the grounds that a restriction on composition must be vague, and vague composition leads, via a precisificational theory of vagueness, to an absurd vagueness of existence. I show how to resist this argument. Unlike the usual resistance, however, I do not jettison precisificational views of vagueness. Instead, I blur the connection between composition and existence that Lewis assumes. On the resulting view, in troublesome cases of vague composition, there is an object, which definitely exists, about which it is vague whether the relevant borderline parts compose it.

We wish to defend Jonathan Westphal's view that colour is complex against a recent ‘phenomenological’ criticism of Eric Rubenstein. There is often thought to be a conflict between two kinds of determinants of colour, physical and phenomenal. On the one hand there are the complex physical facts about colour, such as the determination of a surface colour by an absorption spectrum. There is also, however, the fact that the apparently simple phenomenological quality of what is seen is a function of the physiological and psychological state of the viewing subject. Should the physical trump the phenomenal, or is it the other way round? Much of the phenomenal variation of colour, however, is explained by physical facts. There is a physics and a psychophysics of colour. Colours appear, to the colour scientists at least, to be in some sense objective, a sense not explained by the view that they are purely phenomenal. Taking physics and psychophysics into account will mean rejecting the claim that the content of what our concepts of colours are concepts of is exhausted by the purely phenomenal, or that we can determine these concepts simply by gazing at a colour. Taking account of physics will lead, as Westphal argued, instead to a view about white and the other colour terms like Putnam's account of gold. Necessary truths about colours cannot be explained without reference to the logic of the compossibility of what is given in reflection and absorption spectra, the analogue of H2O.

Variations in colour perception have featured prominently in recent attempts to argue against the view that colours are objective mind-independent properties of the perceptual environment. My aim in this paper is to defend the view that colours are mind-independent properties in response to worries arising from one type of empirically documented case of perceptual variation: variation in the perception of the «unique hues». §1 sets out the challenge raised by variation in the perception of the unique hues. I argue in §2 that the empirical findings are less dramatic than they might initially appear, and in §3 that accounting for the inter-personal differences is consistent with the view that colours are mind-independent properties that normal subjects veridically perceive, at least roughly speaking.

In other words, suppose we sought to describe the conditions under which composition takes place. This is Peter van Inwagen’s “special composition question” [van Inwagen 1990: 21-32]. The thesis of restricted composition rejects two extreme answers to this question: nihilism (according to which C is never satisfied) and universalism (according to which C is always satisfied). Defenders of restricted composition – who say both that composition sometimes takes places, but deny that it always takes places – are faced with the charge that restricted composition entails the vagueness of composition, which is said to be impossible. Here I defend restricted composition against this objection, originally due to David Lewis [1986: 211-13] and elaborated by Ted Sider [2001: 121-32 and 2003].