Online research in philosophy

What all contemporary so-called aristotelian realists have in common has been identified by David Armstrong as the principle of instantiation. This principle has been put forward in different versions, but all of them have the following simple consequence in common: uninstantiated universals do not exist. Such entities are for the lotus-eating Platonist to countenance, but not for any sort of moderate realist. I shall argue that this principle, in any guise, is not the best way to differentiate aristotelianism from Platonism. In its place, I shall suggest that the best way to differentiate the two versions of realism from each other is by means of a far more powerful idea: naturalism. And the surprising conclusion given this means of differentiation will be that contrary to the usual proclamations, Platonism will be the more naturalistic theory, whereas aristotelianism will come to be seen for what it really is, namely, non-naturalistic.

There is a tradition according to which Parmenides of Elea endorsed the following set of counterintuitive doctrines: (a) There exists exactly one material thing. (b) What exists does not change. (g) Nothing is generated or destroyed. (d) What exists is undivided. For convenience, I will use the label ‘Eleatic monism’ to refer to the conjunction of a–d.

Drawing inspiration from the ethical pluralism of G. E. Moore's Principia Ethica, I contend that one empty world can be morally better than another. By ?empty? I mean that it is devoid of concrete entities (things that have a position in space or time). These worlds have no thickets or thimbles, no thinkers, no thoughts. Infinitely many of these worlds have laws of nature, abstract entities, and perhaps, space and time. These non-concrete differences are enough to make some of them better than others. 1I thank Walter Sinnott-Armstrong, John Carroll, and Gideon Rosen for their comments and suggestions.

In this paper it is argued that The Principle of the Identity of Indiscernibles can be justified as a concrete application of Ockham’s Razor, the maxim which enjoins us not to multiply entities beyond necessity. First, a statement of the Principle is presented, according to which the Principle, while interesting enough, is not logically necessary. It is then argued that the assumption of the falsity of the Principle prescribes an epistemological situation where it seems to be impossible to find grounds for thinking that the Principle is indeed false. Hence it is to be accepted as an epistemological necessity of sorts, one that recommended by the desire not to multiply entities beyond need.

This article discusses the argument we cannot have knowledge of abstract entities because they are not part of the causal order. The claim of this article is that the argument fails because of equivocation. Assume that the “causal order” is concerned with contingent facts involving time and space. Even if the existence of abstract entities is not contingent and does not involve time or space it does not follow that no truths about abstract entities are contingent or involve time or space. I argue that it is the latter which is required to obtain the desired conclusion.

A natural way to think of models is as abstract entities. If theories employ models to represent the world, theories traffic in abstract entities much more widely than is often assumed. This kind of thought seems to create a problem for a scientific realist approach to theories. Scientific realists claim theories should be understood literally. Do they then imply (and are they committed to) the reality of abstract entities? Or are theories simply—and incurably—false (if there are no abstract entities)? Or has the very idea of literal understanding to be abandoned? Is then fictionalism towards scientific theories inevitable? This paper argues that scientific realism can happily co-exist with models qua abstracta.

In this article, I will focus on the notion of supervenience introduced and deployed by Armstrong. The aim is to settle the issue of whether it has any fruitful applications. My conclusions are negative. Armstrong gives to his notion of supervenience a major explanatory role of telling why one need not consider certain beings as a genuine ontic expansion, if one already assumes a certain meagre set of more basic entities. On closer inspection, however, Armstrong’s notion does not clarify such intuitions any further. The legitimate uses of the notion for the above purpose turn out to be redundant: the concepts of identity and partial identity can be employed instead.

The Eleatic Principle or causal criterion is a causal test that entities must pass in order to gain admission to some philosophers’ ontology.1 This principle justifies belief in only those entities to which causal power can be attributed, that is, to those entities which can bring about changes in the world. The idea of such a test is rather important in modern ontology, since it is neither without intuitive appeal nor without influential supporters. Its supporters have included David Armstrong (1978, Vol 2, 5), Brian Ellis (1990, 22) and Hartry Field2 (1989, 68) to name but a few.