CHAPTER ONE GENERAL INTRODUCTION
Background of Study
One of the problems which philosophers throughout history have had to grapple with has been the particular nature of the human mind and its interaction with the body. Plato for instance contemplated the nature of the soul and its relationship with the body. He was of the view that the body is the prison house of the soul and that at death the soul is set free from the shackles of the body and returns to the world of forms1. Plato provides a dualistic account of being human, according to the dualistic account there exists a body and there exists a soul, both are distinct and at the death of the body the soul lives on.
During the medieval era, the question of the specific relationship between the soul and the body was a matter of serious contention. According to Thomas Aquinas, the soul is united to the body as its form. Aquinas employs the argument of matter and form as espoused by Aristotle to describe the specific union which exists between the body and the soul. For Aquinas the soul is united to the body to the extent that even after death “the soul….has a natural aptitude and a natural tendency to embodiment”2. Unlike Plato who considers the body to be a hindrance to the full contemplative power of the soul, Aquinas considers the body as providing the needed environmental sensations for the soul to contemplate on.
The question of mind and body interaction was heightened in the Modern era in the Meditations of Rene Descartes. In his search for indubitable knowledge, Descartes arrived at the conclusion that the only thing that he could not doubt was his own existence. After doubting his senses and body he concluded that he existed as a thinking thing; a thing that affirms, doubts, denies and understands, i.e. he existed as a mind. He made the famous statement ‘Cogito ergo sum’ which translates as ‘I think therefore I am’. However as he
1 Bluck, R. S. (2014). Plato’s Phaedo: A Translation of Plato’s Phaedo. London: Routledge.
2 Saint Thomas (Aquinas). (1991). Summa Theologiae: A concise translation. Christian Classics.
progressed in other chapters of his Meditations he affirmed the existence of the body and asserted that the mind interacted with the body. According to Descartes the mind and the body are two distinct substances. While the body is extended, divisible and spatial, the mind is non- extended, indivisible and non-spatial. However in spite of their very distinct properties Descartes asserts that there is a causal interaction between the mind and the body and vice versa3.
The problem with Cartesian dualism can be stated in this way: how is it possible that two substances with distinct properties interact with each other? Rene Descartes’ interactionist dualism led to the mind-body problem in contemporary philosophy of mind. In an attempt to find a solution to the mind-body problem various theories have emerged. These theories can be grouped under two main branches; substance dualism and monism. Substance dualism refers to the belief in the existence of two ontological realms of reality, while monism refers to the belief in one ultimate realm of reality.
Substance dualist’s accounts of the mind-body problem include; interactionist dualism, occasionalism, pre-established harmony and parallelism, while monist accounts of the mind- body problem are idealism and physicalism. It is important to note that occasionalism, pre- established harmony and parallelism attribute physical and mental interaction or causation to an act of God and therefore are not theories which are subject to empirical or scientific examination.
Given the rise of logical positivism and the analytical turn in philosophy, contemporary discussions in philosophy of mind have abandoned theories like occasionalism, parallelism and pre-established harmony which tend to appeal to God for explanations of mental and physical interaction. Most contemporary debates in philosophy of mind have jettisoned
3 Cottingham, J. (1996). René Descartes: Meditations on first philosophy: With selections from the objections and replies. Cambridge: Cambridge University Press.
substance dualism because of the ontological distinction it draws between the mind and the body i.e. the mind as a separate entity existing as a substance outside the body has been jettisoned in philosophy of mind in the same way the phlogiston theory4 has been abandoned in science for the explanation of combustion.
Statement of the Problem
Physicalism posits that reality is made up of the physical or that reality is fundamentally physical, thus everything that exists in the universe is ultimately explainable in physical terms. Another major component of physicalism is that every physical event has a physical cause; this is known as the causal closure of physics. However there has been a popularization of a strand of physicalism known as non-reductive physicalism. This is the view that everything including the mental is ultimately physical or depends on the physical domain but denies that mental phenomena such as consciousness are reducible to physical processes. According to the non-reductive physicalist mental properties are not physical processes and in order to distinguish non-reductive physicalism from epiphenomenalism, the non-reductive physicalist considers mental properties not just as a by-product of physical processes which are causally inert but posits that mental properties can cause physical events thereby violating the principle of the causal closure of physics.
The problem which this thesis seeks to investigate therefore is that, if physicalism suggests that the only reality is the physical kind and that all other things including the mental depends on the physical domain then is the position of the non-reductive physicalist with respect to the independence of mental properties and their causal power consistent with physicalism? Is the non-reductive physicalist a non-physicalist in disguise? Does the non- reductive physicalist succeed in merging Cartesian dualism with the tenets of physicalism and does the result of this merger merit the tag; ‘physicalism’?
4 The phlogiston theory held that the substance which aided in burning was phlogiston. This theory was disproved with scientific progress which showed that the substance which aides burning is oxygen.
Aim and Objectives of Thesis
The main aim of this thesis is to defend non-reductive physicalism as a plausible theory of consciousness. I seek to achieve this aim through the following objectives:
- To argue that reductive physicalism is not adequate in its explanation of consciousness.
- To argue that physicalism need not be reductive.
- To argue that non-reductive physicalists qualify to be characterized as physicalists.
- To argue that non-reductive physicalism does not violate the principle of the causal closure of the physical domain.
- To argue that non-reductive physicalism is a more plausible theory of consciousness than reductive physicalism.
