Change,Difference, and Orthodox Truthmaker Theory

Call the thesis that, possibly, there are two times, t₁ and t₂, such that everything that exists at t₂ also exists at t₁, but some things that exist at t₁ do not exist at t₂ Temporal Change. Call the thesis that, possibly, there are two worlds, w and v, such that everything that exists at v also exists at w, but some things that exist at w do not exist at v Modal Difference. I argue that if either Temporal Change or Modal Difference is true, then Orthodox Truthmaker Theory—the theory that every truth requires a necessitating truthmaker—is false.     

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.     

Grounding,physicalism and necessity

Recent work on metaphysical grounding has suggested that physicalism can be characterised in terms of the mental facts being grounded in physical facts. It is often assumed that the full grounds of a fact metaphysically necessitate that fact. Therefore, it seems that if the physical grounds the mental, then the physical facts metaphysically necessitate the mental facts. Stefan Leuenberger argues that such a version of physicalism would be vulnerable to counterexamples. I shall outline a characterisation of grounding which appeals to a relation between grounding and the essences of properties instantiated in the grounded facts or in their grounds. If a grounded fact is such that its constituent property is essentially related to the properties instantiated in its grounds, or vice versa, then the grounded fact will be metaphysically necessitated by its full grounds. This characterisation of grounding not only avoids Leuenberger’s counterexamples, but has broader implications for characterising physicalism in terms of grounding.     

The problem of extras and the contingency of physicalism

Perhaps all concrete phenomena obtain solely in virtue of physical phenomena. Even so, it seems that the world could have been otherwise. It seems that physicalism, if true, is contingently true. In fact, many believe that the actual truth of physicalism allows metaphysically possible worlds duplicating the actual world in all physical respects while containing immaterial extras, e.g. ghosts, spirits, or Cartesian souls, that no physicalist would believe actually exist. Here I focus on physicalism regarding mentality and argue that the doctrine does not allow possible worlds that physically duplicate the actual world while differing mentally. By revealing what physicalism (regarding the mind) does not allow, this essay helps us get clear on what the view really amounts to and why it is contingent.     

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.