On Categories and A Posteriori Necessity: A Phenomenological Echo

This article argues for two related theses. First, it defends a general thesis: any kind of necessity, including metaphysical necessity, can only be known a priori. Second, however, it also argues that the sort of a priori involved in modal metaphysical knowledge is not related to imagination or any sort of so‐called epistemic possibility. Imagination is neither a proof of possibility nor a limit to necessity. Rather, modal metaphysical knowledge is built on intuition of philosophical categories and the structures they form.     

Modal Objectivity1

It is widely agreed that the intelligibility of modal metaphysics has been vindicated. Quine's arguments to the contrary supposedly confused analyticity with metaphysical necessity, and rigid with non‐rigid designators.² But even if modal metaphysics is intelligible, it could be misconceived. It could be that metaphysical necessity is not absolute necessity – the strictest real (non‐epistemic, non‐deontic) notion of necessity – and that no proposition of traditional metaphysical interest is necessary in every real sense. If there were nothing otherwise “uniquely metaphysically significant” about metaphysical necessity, then paradigmatic metaphysical necessities would be necessary in one sense of “necessary”, not necessary in another, and that would be it. The question of whether they were necessary simpliciter would be like the question of whether the Parallel Postulate is true simpliciter – understood as a pure mathematical conjecture, rather than as a hypothesis about physical spacetime. In a sense, the latter question has no objective answer. In this article, I argue that paradigmatic questions of modal metaphysics are like the Parallel Postulate question. I then discuss the deflationary ramifications of this argument. I conclude with an alternative conception of the space of possibility. According to this conception, there is no objective boundary between possibility and impossibility. Along the way, I sketch an analogy between modal metaphysics and set theory.     

PHYSICAL AND METAPHYSICAL NECESSITY

Abstract:   I propose a different way of thinking about metaphysical and physical necessity: namely that the fundamental notion of necessity is what would ordinarily be called "truth in all physically possible worlds"– a notion which includes the standard physical necessities and the metaphysical ones as well; I suggest that the latter are marked off not as a stricter kind of necessity but by their epistemic status. One result of this reconceptualization is that the Descartes-Kripke argument against naturalism need no longer trouble us. I end by relating the difference between my view and the standard view to the question, whether there could have been a different world than ours.     

On the Reduction of Necessity to Essence

In his influential paper ‘‘Essence and Modality’’, Kit Fine argues that no account of essence framed in terms of metaphysical necessity is possible, and that it is rather metaphysical necessity which is to be understood in terms of essence. On his account, the concept of essence is primitive, and for a proposition to be metaphysically necessary is for it to be true in virtue of the nature of all things. Fine also proposes a reduction of conceptual and logical necessity in the same vein: a conceptual necessity is a proposition true in virtue of the nature of all concepts, and a logical necessity a proposition true in virtue of the nature of all logical concepts. I argue that the plausibility of Fine's view crucially requires that certain apparent explanatory links between essentialist facts be admitted and accounted for, and I make a suggestion about how this can be done. I then argue against the reductions of conceptual and logical necessity proposed by Fine and suggest alternative reductions, which remain nevertheless Finean in spirit.     

WHY ESSENTIALISM REQUIRES TWO SENSES OF NECESSITY

I set up a dilemma, concerning metaphysical modality de re, for the essentialist opponent of a ‘two senses’ view of necessity. I focus specifically on Frank Jackson's two‐dimensional account in his From Metaphysics to Ethics (Oxford: Oxford University Press, 1998). I set out the background to Jackson's conception of conceptual analysis and his rejection of a two senses view. I proceed to outline two purportedly objective (as opposed to epistemic) differences between metaphysical and logical necessity. I conclude that since one of these differences must hold and since each requires the adoption of a two senses view of necessity, essentialism is not consistent with the rejection of a two senses view.¹     

Models and Logical Consequence

This paper deals with the adequacy of the model-theoretic definition of logical consequence. Logical consequence is commonly described as a necessary relation that can be determined by the form of the sentences involved. In this paper, necessity is assumed to be a metaphysical notion, and formality is viewed as a means to avoid dealing with complex metaphysical questions in logical investigations. Logical terms are an essential part of the form of sentences and thus have a crucial role in determining logical consequence. Gila Sher and Stewart Shapiro each propose a formal criterion for logical terms within a model-theoretic framework, based on the idea of invariance under isomorphism. The two criteria are formally equivalent, and thus we have a common ground for evaluating and comparing Sher and Shapiro philosophical justification of their criteria. It is argued that Shapiro's blended approach, by which models represent possible worlds under interpretations of the language, is preferable to Sher’s formal-structural view, according to which models represent formal structures. The advantages and disadvantages of both views’ reliance on isomorphism are discussed.     

Causal Powers and the Necessity of Realization

Non-reductive physicalists hold that mental properties are realized by physical properties. The realization relation is typically taken to be a metaphysical necessitation relation. Here, I explore how the metaphysical necessitation feature of realization can be explained by what is known as ‘the subset view’ of realization. The subset view holds that the causal powers that are associated with a realized property are a proper subset of the causal powers that are associated with the realizer property. I argue that the said explanation of the metaphysical necessitation feature requires a careful treatment of the relationship between properties and causal powers.     

Causal Necessity in Aristotle

Like many realists about causation and causal powers, Aristotle uses the language of necessity when discussing causation, and he appears to think that by invoking necessity, he is clarifying the manner in which causes bring about or determine their effects. In so doing, he would appear to run afoul of Humean criticisms of the notion of a necessary connection between cause and effect. The claim that causes necessitate their effects may be understood— or attacked— in several ways, however, and so whether the view or its criticism is tenable depends on how we understand the necessitation claim. In fact, Aristotelian efficient causation may be said to involve two distinct necessary connections: one is a relation between causes considered as potential, while the other relates them considered as active. That is, the claims that (1) what has the power to heat necessarily heats what has the power to be heated, and that (2) a particular flame which is actually under a pot necessarily heats it, both of which appear to be true for Aristotle, involve distinct notions of necessity. The latter kind of necessity is based on the facts, as Aristotle sees them, about change, whereas the former is based in the nature of properties. Though different, both kinds of necessity are instances of what contemporary philosophers would call metaphysical necessity, and together they also amount to a theory of causal determination.     

Four Questions of Iterated Grounding

The Question of Iterated Grounding (QIG) asks what grounds the grounding facts. Although the question received a lot of attention in the past few years, it is usually discussed independently of another important issue: the connection between metaphysical explanation and the relation or relations that supposedly “back” it. I will show that once we get clear on the distinction between metaphysical explanation and the relation(s) backing it, we can distinguish no fewer than four questions lumped under QIG. I will also argue that given some plausible assumptions about what it would take for a relation to back metaphysical explanation, many salient views about grounding allow us to give “easy” answers to these questions—easy in the sense that we can straightforwardly derive them from the respective conception of grounding without getting into the sorts of complexities that typically inform answers to QIG. The paper's main upshot is that we cannot expect to make much progress on QIG without first addressing the difficult issue of how exactly grounding is related to metaphysical explanation.     

关于克里普克模态性的一个自然主义解释

The Kripkean metaphysical modality (i.e. possibility and necessity) is one of the most important concepts in contemporary analytic philosophy and is the basis of many metaphysical speculations. These metaphysical speculations frequently commit to entities that do not belong to this physical universe, such as merely possible entities, abstract entities, mental entities or qualities not realizable by the physical, which seems to contradict naturalism or physicalism. This paper proposes a naturalistic interpretation of the Kripkean modality, as a naturalist’s response to these metaphysical speculations. It will show that naturalism can accommodate the Kripkean metaphysical modality. In particular, it will show that naturalism can help to resolve the puzzles surrounding Kripke’s a posteriori necessary propositions and a priori contingent propositions. __________ Translated from Zhexue yanjiu 哲学研究 (Philosophical Researches), 2008, (1): 18–26     

Putting modal metaphysics first

I propose that we approach the epistemology of modality by putting modal metaphysics first and, specifically, by investigating the metaphysics of essence. Following a prominent Neo-Aristotelian view, I hold that metaphysical necessity depends on the nature of things, namely their essences. I further clarify that essences are core properties having distinctive superexplanatory powers. In the case of natural kinds, which is my focus in the paper, superexplanatoriness is due to the fact that the essence of a kind is what causes all the many properties and behaviors that are typically shared by all the instances of the kind. Accordingly, we know what is necessarily true of kinds by knowing what is essential to them in the sense of actually playing such causal-explanatory roles. Modal reasoning aimed at discovering metaphysical necessity thus proceeds via essentialist deduction: we move from essentialist truths to reach necessary truths.

     

Can Essence Provide Knowledge of Metaphysical Necessity? A Reply to Jago

Philosophia - In this paper I argue against Mark Jago’s recent suggestion that ordinary knowers can move from knowledge of essence to knowledge of metaphysical necessity.     

On how (not) to define modality in terms of essence

Philosophical Studies - In his influential article ‘Essence and Modality’, Fine proposes a definition of (conceptual, logical and metaphysical) necessity in terms of the primitive...     

The Powerlessness of Necessity

This paper concerns anti‐Humean intuitions about connections in nature. It argues for the existence of a de re link that is not necessity. Some anti‐Humeans tacitly assume that metaphysical necessity can be used for all sorts of anti‐Humean desires. Metaphysical necessity is thought to stick together whatever would be loose and separate in a Hume world, as if it were a kind of universal superglue. I argue that this is not feasible. Metaphysical necessity might connect synchronically co‐existent properties—kinds and their essential features, for example—but it is difficult to see how it could also serve as the binding force for successions of events. That is, metaphysical necessity seems not to be fit for diachronic, causal affairs in which causal laws, causation, or dispositions are involved. A different anti‐Humean connection in nature has to do that job. My arguments focus mainly on a debate which has been the battleground for Humean vs. anti‐Humean intuitions for many decades—namely, the analysis of dispositional predicates—yet I believe (but do not argue here) that the arguments generalise to causation and causal laws straightforwardly.     

No Work for a Theory of Grounding

It has recently been suggested that a distinctive metaphysical relation— ‘Grounding’—is ultimately at issue in contexts in which some goings-on are said to hold ‘in virtue of’’, be (constitutively) ‘metaphysically dependent on’, or be ‘nothing over and above’ some others. Grounding is supposed to do good work (better than merely modal notions, in particular) in illuminating metaphysical dependence. I argue that Grounding is also unsuited to do this work. To start, Grounding alone cannot do this work, for bare claims of Grounding leave open such basic questions as whether Grounded goings-on exist, whether they are reducible to or rather distinct from Grounding goings-on, whether they are efficacious, and so on; but in the absence of answers to such basic questions, we are not in position to assess the associated claim or theses concerning metaphysical dependence. There is no avoiding appeal to the specific metaphysical relations typically at issue in investigations into dependence—for example, type or token identity, functional realization, classical mereological parthood, the set membership relation, the proper subset relation, the determinable/determinate relation, and so on—which are capable of answering these questions. But, I argue, once the specific relations are on the scene, there is no need for Grounding.     

Vagueness and the Laws of Metaphysics

This is a paper about the nature of metaphysical laws and their relation to the phenomenon of vagueness. Metaphysical laws are introduced as analogous to natural laws, and metaphysical indeterminism is modeled on causal indeterminacy. This kind of indeterminacy is then put to work in developing a novel theory of vagueness and a solution to the sorites paradox.     

Metaphysical necessity: a skeptical perspective

Many people hold that there is a distinctive notion of metaphysical necessity. In this paper I explain why I am skeptical about the view. I examine the sorts of considerations that are adduced for it, and argue that they meet equal and opposite considerations.

     

Ibn ʿArabī (1165–1240) and Rūmī (1207–1273) on the Question of Evil: Discontinuities in Sufi Metaphysics

This article compares and contrasts Ibn ?Arabī’s and Rūmī’s accounts of evil. Ibn ?Arabī explains the existence of evil as a consequence of both metaphysical necessity and God’s volitional act. Evil is the inevitable ‘shadow’ of existence implied by the Infinity of God, and God’s mercy existentiates the possibilities ‘hidden’ in the Infinite, allowing this metaphysical necessity to emerge. In contrast to Ibn ?Arabī’s necessitarian-cum-volitional theodicy, Rūmī presents an almost exclusively volitional theodicy. He traces the roots of evil to the Divine Will. To preserve God’s moral perfection, he frequently points to the positive compensating functions of the existence of evil in the world. Ibn ?Arabī’s theodicy enables him to accentuate the necessity of evil in order to save the act of will, and hence God’s perfection, from being directly related to the emergence of evil. Rūmī’s volitional theodicy, however, relates the Divine Will directly to evil, and subsequently attempts to preserve the purity of the Divine intention by accentuating all the positive compensations.     

TWO KINDS OF POSSIBILITY

I defend a version of Kripke's claim that the metaphysically necessary and the knowable a priori are independent. On my version, there are two independent families of modal notions, metaphysical and epistemic, neither stronger than the other. Metaphysical possibility is constrained by the laws of nature. Logical validity, I suggest, is best understood in terms of epistemic necessity.     

Remarks on Bolzano's Conception of Necessary Truth

This essay presents a new interpretation of Bolzano's account of necessary truth as set out in §182 of the Theory of Science. According to this interpretation, Bolzano's conception is closely related to that of Leibniz, with some important differences. In the first place, Bolzano's conception of necessary truth embraces not only what Leibniz called metaphysical or brute necessities but also moral necessities (truths grounded in God's choice of the best among all metaphysical possibilities). Second, in marked contrast to Leibniz, Bolzano maintains that there is still plenty of room for contingency even on this broader conception of necessity.