Consciousness is puzzling. It is something we are immediately aware of, yet at the same time it is equally mysterious. We experience the world but it seems hard to grasp how we can explain our experience adequately to another person. Why do we have an experience of the world and why is this experience subjective? A metaphysical framework will be the main tool in how one approaches and explains the problem of consciousness. There are two broad views that one can adopt in addressing this question. The first is a physicalist view of consciousness. Physicalism is the thesis that human beings are only a physical thing with physical properties and that consciousness can be explained through purely physical processes in the brain. Historically, this view has also been called materialism but over the past hundred years the term physicalism has become more popular, though both can be used interchangeably. Dualism, which is the second view, posits two different things in the ontological framework. There are two positions of dualism in philosophy of mind – property dualism and substance dualism. Property dualism is the view that human beings are a physical substance which has physical properties and irreducible mental properties and that consciousness can be explained in terms of both these physical properties and mental properties. Property dualism treats these properties as being fundamentally different from one another. Substance dualism on the other hand, is the view that humans have both a physical substance – their body – and an immaterial substance – their soul. Under this view these two substances are distinct from one another and interact with one another in a two-way relation. This view also holds that human beings are essentially their soul and that when the body dies the soul can still continue to exist. Advocates of both forms of dualism argue that the physicalist picture is not adequate in explaining what consciousness is and how we have it. A handful of philosophers in the philosophy of mind have been adopting a property dualist view because of skepticism about physicalism’s explanatory power. In this paper I will show that arguments that lead to property dualism are correct as a critique of physicalism’s ability to give an explanatory bridge of consciousness, but I will argue that property dualism is an untenable middle ground position and pushes one towards a substance dualism.
We must first understand what physicalism is in order to understand the context of the critiques of it. I have stated that physicalism is the thesis that human beings are only a physical thing with physical properties and that consciousness can be explained through purely physical processes in the brain. There are different ways as to how the physicalist can address this explanation. Eliminativist theories do not regard consciousness as a thing to be explained because they deny its existence outright. More modest eliminativist views deny certain features of consciousness such as qualia (Gulick). “Qualia is plural for quale, which means a specific experiential quality – for example, what it is like to experience redness or blueness” (Moreland 257). Eliminativism does not regard consciousness as a viable conceptual scheme (Gulick). Behaviorism is the view that mental states can be merely characterized as behavior states. I can know the mental state of a person by observing their behavior. When someone pricks me with a pin, you can determine my pain by my reaction to the pin. Thus, behavior states can be used to explain conscious states (Moreland 250). A type-type identity theory treats physical states as being the same as mental states. This view takes a phenomenal experience such as seeing red as identical to a physical brain state. If mental states are identical to physical brain states then no explanation is needed as to how mental states emerge from physical states (Gulick). A functionalist physicalist theory sees consciousness as a function or role of the brain. This view relies on realizability in order to explain how mental states and physical states relate (Gulick). A common analogy to explain this view is the difference between computer hardware and software. Philosopher J.P. Moreland says that “this is similar to requiring that only some sort of physical hardware can be the realizer of functional roles specified in computer software.” Functionalism does not regard mental states as having intrinsic features but only extrinsic features by the roles they play within the organism (Moreland 249).
It is important to discuss the notion of supervenience in philosophy of mind and more importantly how it relates to functionalism. In his book Mind, Brain, and Free Will, Richard Swinburne says that “functionalists claim that science has shown that the only events in humans caused by input to sense-organs and causing behavioural output are brain events. Hence many brain events are events with functional properties which supervene on brain properties” (95) Terence Horgan defines supervenience as:
a determination relation between properties or characteristics of objects. The basic idea is this: properties of type A are supervenient on properties of type B if and only if two objects cannot differ with respect to their A-properties without also differing in their B-properties (150).
For example, “a utilitarian may urge that moral properties supervene on properties measuring human happiness.” So, if there is a change in the properties measuring human happiness, there is a change in the moral properties according to the utilitarian (Swinburne 22). It is important to have this definition of supervenience when discussing concepts in the philosophy of mind. Given these brief sketches of some physicalist pictures of consciousness, I will now show how other philosophers have responded to these views. Type-type and functionalist views are the two most popular of the four. Behaviorism is rejected by most physicalists, and eliminativism does not even enter the discussion on consciousness. Consequently, this paper will focus on the former two views.
Gulick, Robert Van. “Physicalist Theories.” Stanford University. Stanford University, 18 June 2004. Web. 27 May 2015. <http://plato.stanford.edu/entries/consciousness/#PhyThe>.
Horgan, Terence. “From Supervenience to Superdupervenience.” Philosophy of Mind: Classical and Contemporary Readings. New York: Oxford UP, 2002. 150-62. Print.
Moreland, James Porter, and William Lane. Craig. “Dualism and Alternatives to Dualism.” Philosophical Foundations for a Christian Worldview. Downers Grove, IL: InterVarsity, 2003. 228-66. Print.
Swinburne, Richard. Mind, Brain, and Free Will. Oxford: Oxford UP, 2013. Print.