A review of recent work on physicalism, focusing on what it means to say nothing exists over and above the physical, how "the physical" should be defined, and the causal argument for physicalism.

As a first pass, physicalism is the doctrine that there is nothing over and above the physical. Much recent philosophical work has been devoted to spelling out what this means in more rigorous terms and to assessing the case for the view. What follows is a survey of such work. I begin by looking at competing accounts of what is meant by nothing over and above and then turn to how the physical should be understood. Once we are clear on (...) the options for formulating the physicalist thesis, we will look at the leading argument for the view. Along the way, I will suggest avenues for further exploration. (shrink)

It is widely thought that there is an important argument to be made that starts with premises taken from the science of physics and ends with the conclusion of physicalism. The standard view is that this argument takes the form of a causal argument for physicalism. Roughly, physics tells us that the physical realm is causally complete, and so minds (among other entities) must be physical if they are to interact with the world as we think they do. In what (...) follows, I raise problems for this view. After an initial review of the causal argument, I begin my case by showing that the totality of physical truths do not deductively entail the causal completeness of the physical realm, using a double-prevention scenario and causation by omission to show that nonphysical causes of physical effects would not need to violate physical conservation laws. I then move on to raise problems for an inductive argument for causal completeness by drawing on the neo-Russellian view that there is no causation in fundamental physics, and so causation must itself be a realized or derived entity. I conclude by suggesting that the underlying problem is that the causal argument has fallen out of touch with the sophisticated understanding that philosophers have developed of the role of causation within physics. (shrink)

Dualism holds that some mental events are fundamental and non-physical. I develop a prima facie plausible causal argument for dualism. The argument has several significant implications. First, it constitutes a new way of arguing for dualism. Second, it provides dualists with a parity response to causal arguments for physicalism. Third, it transforms the dialectical role of epiphenomenalism. Fourth, it refutes the view that causal considerations prima facie support physicalism but not dualism. After developing the causal argument for dualism and drawing (...) out these implications, I subject the argument to a battery of objections. Some prompt revisions to the argument. Others reveal limitations in scope. It falls out of the discussion that the causal argument for dualism is best used against physicalism as a keystone in a divide and conquer strategy. (shrink)

Though there is yet no consensus on the right way to understand ‘physicalism’, most philosophers agree that, regardless of whatever else is required, physicalism cannot be true if there exists fundamental mentality. I will follow Jessica Wilson (Philosophical Studies 131:61–99, 2006) in calling this the 'No Fundamental Mentality' (NFM) constraint on physicalism. Unfortunately for those who wish to constrain physicalism in this way, NFM admits of a counterexample: an artificially intelligent quantum computer which employs quantum properties as part of its (...) cognitive operations. If one of these quantum properties serves a proper functional role in the artificial intelligence, then that property counts as a mental under the physicalism-friendly theory of mentality called “realizer functionalism”, which says that a lower-order property is mental if it satisfies an appropriate higher-order functional description. Further, if this quantum property is both fundamental and mental, then NFM must rule that it is not physical. Yet the existence of such an artificially intelligent quantum computer, which possesses mental properties solely in virtue of the functional roles those properties play, is surely consistent with the truth of physicalism. This ought to motivate NFM proponents to reformulate their view. (shrink)

Regardless of whatever else physicalism requires, nearly all philosophers agree that physicalism cannot be true in a world which contains fundamental mentality. I challenge this widely held attitude, and describe a world which is plausibly all-physical, yet which may contain fundamental mentality. This is a world in which priority monism is true—which is the view that the whole of the cosmos is fundamental, with dependence relations directed from the whole to the parts—and which contains only a single mental system, like (...) a brain or computer. Because some properties of the whole are fundamental under priority monism, it follows that that the mental properties of a cosmos-encompassing brain or computer system may be fundamental in a priority monist world. Yet such a world need not contain anything physically unacceptable: the mental properties of the cosmos-encompassing brain or computer can be characterized in a physicalism-friendly functionalist or identity-theoretic way. Thus, as I see it, physicalism need not be false in such a world. This constitutes a challenge to those who hold the view that physicalism is inconsistent with the existence of fundamental mentality. (shrink)

Extensional articulations of physicalism define what it means to be physical relative to the properties of a set of entities, such that physicalism is true if the fundamental properties which compose the entities in this set are the same sorts of fundamental properties which compose everything that exists. Here I present a novel problem for these articulations of physicalism: they are consistent with phenomenal idealism, which is the view that only phenomenal properties exist. Under this view, paradigm physical objects such (...) as tables and chairs are constructed out of more basic phenomenal properties. Since this view says that everything—including paradigm physical entities—is ultimately constituted by phenomenal properties, it follows that this view is consistent with extensional definitions of physicalism, since such definitions only require that there be no fundamental difference between paradigm physical entities and everything else. Yet a good definition of physicalism should not be consistent with phenomenal idealism. (shrink)

Physicalism demands an explication of what it means for something to be physical. But the most popular way of providing one—viz., characterizing the physical in terms of the postulates of a scientifically derived physical theory—is met with serious trouble. Proponents of physicalism can either appeal to current physical theory or to some future physical theory (preferably an ideal and complete one). Neither option is promising: currentism almost assuredly renders physicalism false and futurism appears to render it indeterminate or trivial. The (...) purpose of this essay is to argue that attempts to characterize the mental encounter a similar dilemma: currentism with respect to the mental is likely to be inadequate or contain falsehoods and futurism leaves too many significant questions about the nature of mentality unanswered. This new dilemma, we show, threatens both sides of the current debate surrounding the metaphysical status of the mind. (shrink)