1.Following Kripke, many philosophers have accepted the existence of propositions concerning essences, and, more generally, propositions asserting necessities, that are knowable only a posteriori. Such an acceptance is consistent with the claim that ultimately all knowledge of necessity is a priori. A posteriori knowledge of necessity may be held to be a consequence of the combination of a priori knowledge of a proposition asserting essence or necessity with a posteriori knowledge of a non-modal proposition. E. J. Lowe (2007: 287–88) denies (...) even this kind of derived a posteriori knowledge of essence or necessity. He reconstructs the form of an argument that is intended to lead to a proposition concerning essence but which is known a posteriori: This schema may be exemplified thus: As this example illustrates, instances of (1) are a priori propositions concerning essence, while instances of (2) are a posteriori propositions; instances of the conclusion are propositions asserting particular essences, and are, it is claimed, knowable only a posteriori.1. (shrink)

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. (shrink)

One type of deflationism about metaphysical modality suggests that it can be analysed strictly in terms of linguistic or conceptual content and that there is nothing particularly metaphysical about modality. Scott Soames is explicitly opposed to this trend. However, a detailed study of Soames’s own account of modality reveals that it has striking similarities with the deflationary account. In this paper I will compare Soames’s account of a posteriori necessities concerning natural kinds with the deflationary one, specifically Alan Sidelle’s account, (...) and suggest that Soames’s account is vulnerable to the deflationist’s critique. Furthermore, I conjecture that both the deflationary account and Soames’s account fail to fully explicate the metaphysical content of a posteriori necessities. Although I will focus on Soames, my argument may have more general implications towards the prospects of providing a meaning-based account of metaphysical modality. (shrink)

In his famous essentialist account of identity, Kripke holds that it is necessary to the identity of individual people that they have the parents they do in fact have. Some have disputed this requirement, treating it either as a reason to reject essentialism or as something that should be eliminated in order to make essentialism stronger. I examine the reasoning behind some of these claims and argue that it fails to acknowledge the complex and multi-faceted importance of biological process in (...) determining identity and distinguishing significant differences between biological and non-biological cases. In fact, this failure derives from an inherent tendency to treat the biological case in just the same way as the non-biological case at least at one important point in its history—the point of formation. This analysis offers a way of salvaging Kripke’s original claims. I focus in particular on the views of Graeme Forbes and Teresa Robertson, but also discuss the views of Nathan Salmon, M. S. Price and E. J. Lowe. (shrink)

In Lowe (2007), I queried the validity of the following inference-schema: This issue is an important one, because it seems to be something like this schema that is relied upon by those philosophers who seek to establish a posteriori truths about the essences of particular entities – notably, particular chemical substances, such as water and gold – by appeal to a combination of empirical information about those entities and certain (alleged) essential truths of a general and a priori character. As (...) one illustration of schema (I), I cited the following inference: I raised various doubts about the validity of this particular inference, whose conclusion (3a) is, if true, an a posteriori truth about the essence of a particular man, John. (Clearly, if the truth of (3a) can be established only by inference from (1a) and (2a), then, since (2a) is undoubtedly an a posteriori claim, (3a) can only be an a posteriori truth.) I also raised more general doubts about schema (I). (shrink)

The paper argues against Peacocke's moderate rationalism in modality. In the first part, I show, by identifying an argumentative gap in its epistemology, that Peacocke's account has not met the Integration Challenge. I then argue that we should modify the account's metaphysics of modal concepts in order to avoid implausible consequences with regards to their possession conditions. This modification generates no extra explanatory gap. Yet, once the minimal modification that avoids those implausible consequences is made, the resulting account cannot support (...) Peacocke's moderate rationalism. (shrink)

According to Essentialism, an object’s properties divide into those that are essential and those that are accidental. While being human is commonly thought to be essential to Socrates, being a philosopher plausibly is not. We can motivate the distinction by appealing—as we just did—to examples. However, it is not obvious how best to characterize the notion of essential property, nor is it easy to give conclusive arguments for the essentiality of a given property. In this paper, I elaborate on these (...) issues and explore the way in which essential properties behave in relation to other related properties, like sufficient-for-existence properties and individual essences. (shrink)

The paper presents a dilemma for both epistemic and non-epistemic versions of conceivability-based accounts of modal knowledge. On the one horn, non-epistemic accounts do not elucidate the essentialist knowledge they would be committed to. On the other, epistemic accounts do not elucidate everyday life de re modal knowledge. In neither case, therefore, do conceivability accounts elucidate de re modal knowledge.

There is currently intense interest in the question of the source of our presumed knowledge of truths concerning what is, or is not, metaphysically possible or necessary. Some philosophers locate this source in our capacities to conceive or imagine various actual or non-actual states of affairs, but this approach is open to certain familiar and seemingly powerful objections. A different and ostensibly more promising approach has been developed by Timothy Williamson, according to which our capacity for modal knowledge is just (...) an extension, or by-product, of our general capacity to acquire knowledge of true counterfactual conditionals — a capacity that we deploy ubiquitously in everyday life. Williamson’s account crucially involves a thesis to the effect that modal truths can be explained in terms of counterfactual truths. In this paper, I query Williamson’s account on a number of points, including this thesis. My positive proposal, which owes a debt to the work of Kit Fine on modality and essence, appeals instead to our capacity to grasp essences, understood in a neo-Aristotelian fashion, according to which essences are expressed by ‘real definitions’. (shrink)

During the last quarter of a century, a number of philosophers have become attracted to the idea that necessity can be analyzed in terms of a hyperintensional notion of essence. One challenge for proponents of this view is to give a plausible explanation of our modal knowledge. The goal of this paper is to develop a strategy for meeting this challenge. My approach rests on an account of modality that I developed in previous work, and which analyzes modal properties in (...) terms of the notion of a metaphysical law. I discuss what information about the metaphysical laws is required for modal knowledge. Moreover, I describe two ways in which we might be able to acquire this information. The first way employs inference to the best explanation. The metaphysical laws, including the essential truths, play a crucial role in causal and grounding explanations and we can gain knowledge of these laws by abductive inferences from facts of which we have perceptual or a priori knowledge. The second way of gaining information about the metaphysical laws rests on knowledge that is partly constitutive of competence with the concepts that are needed to express the relevant information. Finally, I consider how knowledge of the metaphysical laws can be used to establish modal claims, paying special attention to the much-discussed connection between conceiving and possibility. (shrink)

Amie Thomasson has argued against descriptivism about modality, which starts from the idea that modal statements serve to track features of the world and that these features explain the truth-values of modal claims. Thomasson objects that descriptivists cannot satisfactorily explain how modal features fit into the naturalistic picture of the world and that they cannot account for our apparent capacity to acquire modal knowledge. On Thomasson’s alternative to descriptivism (called ‘normativism’), the function of modal claims is to facilitate communication about (...) certain semantic rules. I argue that it is not obvious that the semantic rules that Thomasson takes to be expressed by modal truths really exist. Moreover, I defend a specific version of descriptivism – essentialism – against Thomasson’s objections. Essential truths play a central role in the best explanations of many facts about the world. That includes the explanations delivered by our best scientific theories once these theories are correctly interpreted philosophically. In this way, essences earn their keep in a naturalistic view of the world. Furthermore, the abductive methods by which we confirm our explanatory theories also support certain theses about essences. This allows essentialists to explain knowledge of essences and modal knowledge. (shrink)

In the addenda to his Naming and Necessity, Kripke provides an account of how necessary aposteriori statements are possible. In such a case, there is an apriori general principle telling us that it is necessary if true at all. Though straightforward in its broad compass, this account faces two obvious questions in its application: in each case of necessary aposteriori statements, what is the underlying principle and how is it established apriori? I treat these questions with respect to theoretical identity (...) statements concerning chemical substances, such as ‘water is H2OH2O’. I argue that the general principle underlying the necessity of the statements is that if a chemical substance has a certain chemical composition, then it could not have had any other chemical composition. Then I defend the view that the principle is a conceptual truth by providing a novel derivation of it from the theoretical concept of chemical substance with a sufficient level of formal rigor. The logical principles required for the derivation will also be stated and defended. (shrink)

There is a perennial philosophical dream of a certain natural order for the natural kinds. The name of this dream is ‘the hierarchy requirement’. According to this postulate, proper natural kinds form a taxonomy which is both unique and traditional. Here I demonstrate that complex scientific objects exist: objects which generate different systems of scientific classification, produce myriad legitimate alternatives amongst the nonetheless still natural kinds, and make the hierarchical dream impossible to realize, except at absurdly great cost. Philosophical hopes (...) for a certain order in nature cannot be fulfilled. Natural kinds crosscut one another, ubiquitously so, and this crosscutting spells the end of the hierarchical dream. (shrink)

In this paper I discuss a central objection against diseases being natural kinds—namely, that diseases are processes or transitions and hence they should not be conceptualized in the ‘substantish’ framework of natural kinds. I indicate that the objection hinges on conceiving disease kinds as phase kinds, in contrast to the non-phase, natural kinds of the exact sciences. I focus on somatic diseases and argue, via a representative comparison, that if disease kinds are phase kinds, then exact science kinds are phase (...) kinds as well. On the other hand, if exact science kinds are non-phase kinds, then disease kinds are non-phase kinds as well. This objection should thus be rejected, under a certain caveat, though. If natural kind membership has an influence over the diachronic identity of kind members, then it is possible, in principle, to draw the phase/non-phase distinction such that an ‘ontological gap’ lies between medical kinds and exact science kinds. I show further that this caveat is unavoidable even in relation to substantive universals and ‘essential’ properties—two controversial, strong features that were traditionally associated to natural kinds. (shrink)

The purpose of this thesis is to demonstrate that metaphysics is a necessary discipline -- necessary in the sense that all areas of philosophy, all areas of science, and in fact any type of rational activity at all would be impossible without a metaphysical background or metaphysical presuppositions. Because of the extremely strong nature of this claim, it is not possible to put forward a very simple argument, although I will attempt to construct one. A crucial issue here is what (...) metaphysics in fact is -- the nature of metaphysics. The conception of metaphysics which I support could be called Aristotelian, as opposed to Kantian: metaphysics is the first philosophy and the basis of all other philosophical and scientific inquiry. I will argue that this is indeed the most plausible conception of metaphysics. (shrink)