The Mind-Body Problem in Philosophy: Exploring the Relationship Between Mental and Physical Phenomena
VI – The Mind-Body Problem
VI.1. Mind and Body
VI.1.1. The Mental and Physical Distinction
We owe the mental-physical distinction as we currently understand it to René Descartes (1596-1650). For him, the physical is res extensa (extended substance) and the mental is res cogitans (thinking substance). In philosophy of mind, the fact that something is considered physical does not imply that it is not mental. Some theories claim that mental phenomena are physical (physicalism), while others claim that physical phenomena are mental (idealism).
One definition of “physical” can be the Cartesian one in terms of extension: physical entities have the property of taking up space. The problem is that things like electrons have no extension but seem nevertheless physical. Also, we could define the physical in terms of things composed of matter, but energy is the main category in modern physics. So, we are going to define “physical” more broadly by the descriptive and explanatory resources of modern physics with no further precision; that is, things subject to the laws of physics.
The “mental” could then be defined by the descriptive and explanatory resources of psychological discourse (of folk psychology, not necessarily scientific psychology). Mental phenomena are the kind of things to which we attribute predicates such as “believes” or “desires”. The mental has certain important features which have to be pointed out:
a) First-Person Authority:
The knowledge each of us has of his or her own mental states is in some sense privileged. This doesn’t imply infallibility or incorrigibility: I can be wrong about what I believe, desire, or feel, and other people can correct me about what I believe, desire, or feel. But if I’m mistaken, the burden of proof is on others; firstly, my convictions have to be considered accurate. From this authority, some philosophers have inferred that the mental is an inner domain of private experiences to which only the person experiencing them has direct and non-inferential (with no need of reasoning or proof, non-deductive) access, whereas other people’s access to my mental states is indirect and inferential (I can keep my thoughts secret, my sensations are non-transferable, and my intentions can be easily misinterpreted). Nevertheless, the discussion of the internal/external, inner/outer, private/public, subjective/objective character of the mental is an important part of the mind-body problem, so it cannot be assumed from the beginning the subjective character of mental states without begging the question. The first-person authority is a much more modest assumption.
b) Phenomenal Consciousness and Qualia:
The notion of “consciousness” does not refer here to mere awareness (or self-awareness) as opposed to “unconsciousness”, but to the phenomenal aspects of experiences. Those phenomenal aspects are usually referred to as “qualia” (literally “qualities” in Latin), the qualitative aspects of any mental state, the “something it is like” (the “quale” in singular) to live through. I may describe my pleasure when eating ice cream and be very precise about it, but nevertheless, my description is not “like the pleasure of eating ice cream”; the quale (the qualitative experience) of feeling that pleasure is absent in my description. Both phenomenal consciousness or qualia are concepts which express the idea of third-person inaccessibility to mental states and therefore are not always accepted as valid by philosophers who deny the subjective/objective divide.
c) Intentionality:
It is the feature some mental states have of being directed at something, of being ‘about’ (like my beliefs) or ‘of’ (like my fear) or ‘for’ (like my hope) something. The word “intentionality” derives from the Latin word “intensio”, which was used to describe an archer with his bow drawn (having the bow in tension, aimed at a target), but it is not “intending” (“intention” in this sense is just one possible intentional mental state). Intentionality is the “aboutness” of mental states, and it is an important feature of it that what those mental states are about, or of, or for need not exist (I may fear zombies, werewolves, or witches). Mental states such as beliefs and desires can be expressed as propositional attitudes because they’re expressed as attitudes toward certain propositions (“I believe that philosophy is interesting” or “I desire that philosophy is interesting” express my attitude toward the proposition “philosophy is interesting”; I’m taking a certain stance toward it: I believe it is true or I desire it to be the case).
d) Rationality:
It is the idea that to describe people’s behavior in terms of intentional mental states is to classify that behavior as something that is explainable by appeal to reasons. “Reasons” are a special kind of explanatory cause which appeals to the language of psychology and not of physics. We appeal to reasons when we say things such as “he switched on the light because he wanted to see better” as opposed to “he switched on the light because his fingers pressed the switch”; this is a non-rational explanation of this behavior (non-rational doesn’t mean irrational).
First-person authority (understood as subjectivity) and qualia are central to private conceptions of mental phenomena (those which take these phenomena to be inner, subjective occurrences to which only the individual person experiencing them has direct access). Intentionality and rationality are crucial for public conceptions of mental phenomena (those which take these phenomena to consist in the various ways we comport ourselves toward engagement with the world, ways which can be described and evaluated in rational terms).
VI.1.2. Mind-Body Problems
Mind-body problems have two features in common: the distinction between mental phenomena and physical phenomena, and premises that make it difficult to understand how mental and physical phenomena are related. Those problems arise when we try to understand how thought, feeling, perception, action, and other mental phenomena are related to events in the human nervous system. In our everyday life, we take ourselves to be free beings who act as we do because we have beliefs, desires, hopes, and fears. In our scientific dealings, however, we see the universe as a vast sea of matter and energy, and at a fundamental level, there is no difference between humans and rocks, trees, or animals; all of them are made of subatomic particles which have no beliefs or desires, hopes, or fears.
We thus confront two images of human life: the everyday, pre-scientific image of ourselves as free, rational beings with mental and moral lives, and the scientific image of ourselves as complex biochemical systems.
VI.1.2.1. The Problem of Psychophysical Emergence
Life and mind did not always exist in the universe. This suggests that the physical conditions that existed before their emergence had to be responsible in some way for bringing them about. We are conscious beings with mental states, yet we are composed entirely of non-conscious parts such as molecules. How do our conscious experiences emerge from these non-conscious physical interactions? It seems that if n physical particles are insufficient to produce consciousness, then n+1 particles will be insufficient as well, and in that case, it looks like no number of subatomic collisions will be sufficient to produce conscious experiences. How, then, did consciousness manage to emerge in the course of the universe’s history? And how, for that matter, does consciousness manage to emerge in you and me right now?
This is the problem of psychophysical emergence, and in order to solve it, we could try to prove, for instance, either that we’re not conscious beings (eliminative physicalism), or that we’re not entirely composed of non-conscious parts (substance dualism and idealism), or that a certain number of non-conscious parts could combine to produce a conscious whole (dual-attribute theory, reductive physicalism, and non-reductive physicalism).
VI.1.2.2. The Problem of Other Minds
There is a tension between our objective, third-person knowledge of human behavior and our apparently subjective, first-person knowledge of our own conscious states. We often know through ordinary interactions with them what other people think and how they feel, yet mental states seem to be a private, subjective phenomenon. But if thoughts and feelings seem to belong to a private, inner domain of subjective experiences, then other people cannot know what my mental states are; in fact, they cannot even know whether I have any mental states since a human body seems capable of operating in just the way it does without having any conscious states at all (they might simply be automata that act in every way as if they have conscious experiences like mine, while yet having no inner mental life at all). How, then, is it possible to have the knowledge of people we ordinarily take ourselves to have?
This is the problem of other minds, and in order to solve it, we could try to prove, for instance, that it is false that we often know what other people think and how they feel (most dualisms) or that mental states belong to a private, subjective domain (most physicalisms).
VI.1.2.3. The Problem of Mental Causation
Another tension is that between our commonsense understanding of people’s reasons for performing actions and our scientific understanding of the physical mechanisms involved in their performance. I assume that my mental states are responsible for producing my actions; that is, actions appear to be physical events with mental causes. Physical events, however, can be triggered by other physical events. Is …