Research
My primary research interests are in contemporary analytic metaphysics and the methodology of metaphysics, especially a priori knowledge, modality, and essences, but I also have research interests in philosophical logic, epistemology, philosophy of mind, and philosophy of science.
In my Ph.D. thesis, The Necessity of Metaphysics (1Mb PDF), I argue for a rigorously realist, Aristotelian understanding of metaphysics and defend the role of metaphysics in contemporary analytic philosophy. The central themes of the thesis concern a priori knowledge, modality, and essences.
I am currently working on a book provisionally entitled A Study of the Foundations of Metaphysics: Apriority, Modality, and Essence, which develops the main themes of my PhD thesis. I am also the editor of Contemporary Aristotelian Metaphysics (Cambridge University Press, 2012). The volume brings together leading philosophers working in or at least sympathetic to what could be called ‘Aristotelian metaphysics’, that is, metaphysics conceived in a realist fashion, as the ‘first philosophy’.
Published Work
What is our epistemic access to metaphysical modality? Timothy Williamson suggests that the epistemology of counterfactuals will provide the answer. This paper challenges Williamson's account and argues that certain elements of the epistemology of counterfactuals that he discusses, namely so called background knowledge and constitutive facts, are already saturated with modal content which his account fails to explain. Williamson's account will first be outlined and the role of background knowledge and constitutive facts analysed. Their key role is to restrict our imagination to rule out irrelevant counterfactual suppositions. However, background knowledge turns out to be problematic in cases where we are dealing with metaphysically possible counterfactual suppositions that violate the actual laws of physics. As we will see, unless Williamson assumes that background knowledge corresponds with the actual, true laws of physics and that these laws are metaphysically necessary, it will be difficult to address this problem. Furthermore, Williamson's account fails to accommodate the distinction between conceivable yet metaphysically impossible scenarios, and conceivable and metaphysically possible scenarios. This is because background knowledge and constitutive facts are based strictly on our knowledge of the actual world. Williamson does attempt to address this concern with regard to metaphysical necessities – as they hold across all possible worlds – but we will see that even in this case the explanation is questionable. These problems, it will be suggested, cannot be addressed in a counterfactual account of the epistemology of modality. The paper finishes with an analysis of Williamson's possible rejoinders and some discussion about the prospects of an alternative account of modal epistemology.
This is a critical commentary on Kathrin Koslicki's book, The Structure of Objects (2008, OUP)
The distinction between a priori and a posteriori knowledge has been the subject of an enormous amount of discussion, but the literature is biased against recognizing the intimate relationship between these forms of knowledge. For instance, it seems to be almost impossible to find a sample of pure a priori or a posteriori knowledge. In this paper, it will be suggested that distinguishing between a priori and a posteriori is more problematic than is often suggested, and that a priori and a posteriori resources are in fact used in parallel. We will define this relationship between a priori and a posteriori knowledge as the bootstrapping relationship. As we will see, this relationship gives us reasons to seek for an altogether novel definition of a priori and a posteriori knowledge. Specifically, we will have to analyse the relationship between a priori knowledge and a priori reasoning, and it will be suggested that the latter serves as a more promising starting point for the analysis of aprioricity. We will also analyse a number of examples from the natural sciences and consider the role of a priori reasoning in these examples. The focus of this paper is the analysis of the concepts of a priori and a posteriori knowledge rather than the epistemic domain of a posteriori and a priori justification.
This paper challenges the Kripkean interpretation of a posteriori necessities. It will be demonstrated, by an analysis of classic examples, that the modal content of supposed a posteriori necessities is more complicated than the Kripkean line suggests. We will see that further research is needed concerning the a priori principles underlying all a posteriori necessities. In the course of this analysis it will emerge that the modal content of a posteriori necessities can be best described in terms of a Finean conception of modality – by giving essences priority over modality. The upshot of this is that we might be able to establish the necessity of certain supposed a posteriori necessities by a priori means.
The goals of this paper are two-fold: I wish to clarify the Aristotelian conception of the law of non-contradiction as a metaphysical rather than a semantic or logical principle, and to defend the truth of the principle in this sense. First I will explain what it in fact means that the law of non-contradiction is a metaphysical principle. The core idea is that the law of non-contradiction is a general principle derived from how things are in the world. For example, there are certain constraints as to what kind of properties an object can have, and especially: some of these properties are mutually exclusive. Given this characterisation, I will advance to examine what kind of challenges the law of noncontradiction faces—the main opponent here is Graham Priest. I will consider these challenges and conclude that they do not threaten the truth of the law of noncontradiction understood as a metaphysical principle.
In this paper I offer a counterexample to the so called vagueness argument against restricted composition. This will be done in the lines of a recent suggestion by Trenton Merricks, namely by challenging the claim that there cannot be a sharp cut-off point in a composition sequence. It will be suggested that causal powers which emerge when composition occurs can serve as an indicator of such sharp cut-off points. The main example will be the case of a heap. It seems that heaps might provide a very plausible counterexample to the vagueness argument if we accept the idea that four grains of sand is the least number required to compose a heap—the case has been supported by W. D. Hart. My purpose here is not to put forward a new theory of composition, I only wish to refute the vagueness argument and point out that we should be wary of arguments of its form.
In this paper I will offer a novel understanding of a priori knowledge. My claim is that the sharp distinction that is usually made between a priori and a posteriori knowledge is groundless. It will be argued that a plausible understanding of a priori and a posteriori knowledge has to acknowledge that they are in a constant bootstrapping relationship. It is also crucial that we distinguish between a priori propositions that hold in the actualworld and merely possible, non-actual a priori propositions, as we will see when considering cases like Euclidean geometry. Furthermore, contrary to what Kripke seems to suggest, a priori knowledge is intimately connected with metaphysical modality, indeed, grounded in it. The task of a priori reasoning, according to this account, is to delimit the space of metaphysically possible worlds in order for us to be able to determine what is actual.
The priority monist holds that the cosmos is the only fundamental object, of which every other concrete object is a dependent part. One major argument against monism goes back to Russell, who claimed that pluralism is favoured by common sense. However, Jonathan Schaffer turns this argument on its head and uses it to defend priority monism. He suggests that common sense holds that the cosmos is a whole, of which ordinary physical objects are arbitrary portions, and that arbitrary portions depend for their existence on the existence of the whole.
In this paper, we challenge Schaffer's claim that the parts of the cosmos are all arbitrary portions. We suggest that there is a way of carving up the universe such that at least some of its parts are not arbitrary. We offer two arguments in support of this claim. First, we shall outline semantic reasons in its favour: in order to accept that empirical judgements are made true or false by the way the world is, one must accept that the cosmos includes parts whose existence is not arbitrary. Second, we offer an ontological argument: in order for macro-physical phenomena to exist, there must be some micro-physical order which they depend upon, and this order must itself be non-arbitrary.
We conclude that Schaffer's common sense argument for monism cannot be made to work.
This paper is a survey of the positive and negative aspects of cannabis use from the point of view of the individual on the one hand and from the point of view of the society on the other hand. Health, social, and political motives are all discussed, and the best method of harm reduction is analysed. The upshot is that zero tolerance policy is obsolete, and that there are reasons to think that many individuals would be better off using cannabis rather than other drugs.
The purpose of this paper is to examine the status of logic from a metaphysical point of view – what is logic grounded in and what is its relationship with metaphysics. There are three general lines that we can take. 1) Logic and metaphysics are not continuous, neither discipline has no bearing on the other one. This seems to be a rather popular approach, at least implicitly, as philosophers often skip the question altogether and go about their business, be it logic or metaphysics. However, it is not a particularly plausible view and it is very hard to maintain consistently, as we will see. 2) Logic is prior to metaphysics and has metaphysical implications. The extreme example of this kind of approach is the Dummettian one, according to which metaphysical questions are reducible to the question of which logic to adopt. 3) Metaphysics is prior to logic, and your logic should be compatible with your metaphysics. This approach suggests an answer to the question of what logic is grounded in, namely, metaphysics. Here I will defend the third option.
In this paper I examine what exactly is ‘Aristotelian metaphysics’. My inquiry into Aristotelian metaphysics should not be understood to be so much concerned with the details of Aristotle's metaphysics. I am are rather concerned with his methodology of metaphysics, although a lot of the details of his metaphysics survive in contemporary discussion as well.
This warrants an investigation into the methodological aspects of Aristotle's metaphysics. The key works that we will be looking at are his Physics, Metaphysics, Categories and De Interpretatione. Perhaps the most crucial features of the Aristotelian method of philosophising are the relationship between science and metaphysics, and his defence of the principle of non-contradiction (PNC). For Aristotle, natural science is the second philosophy, but this is so only because there is something more fundamental in the world, something that natural science – a science of movement – cannot study. Furthermore, Aristotle demonstrates that metaphysics enters the picture at a fundamental level, as he argues that PNC is a metaphysical rather than a logical principle.
The upshot of all this is that the Aristotelian method and his metaphysics are not threatened by modern science, quite the opposite. Moreover, we have in our hands a methodology which is very rigorous indeed and worthwhile for any metaphysician to have a closer look at.
Work in Progress






