Preparing for Quiz 7
In this section we think about a central question of metaphysics (ontology): what kind of thing is consciousness, or mind, or "soul"?
If Cartesian dualism is correct, the mind is "spiritual substance" (res cogitans) while the body is material substance (res extensa). But why should we believe spiritual substance exists at all? After all, spiritual substances by definition are spiritual; they can't be sensed in any way.
A statement is said to be compatible with all states of affairs if no evidence proves it false. Examples include statements of astrology and New Age claims. They are impossible to disprove; they are true no matter what actually happens. For example, if your horoscope said "You may feel disappointed today", then the horoscope is true whether or not you feel disappointed. If you feel disappointed, it turns out true; if you don't feel disappointed, then it's still true, because it did not say you would feel disappointed; it said you may feel disappointed. You can't prove it's false that you may feel disappointed today, because whatever happens, it's true that you may feel disappointed today.
Just because a statement is compatible with all states of affairs doesn't mean we should put much faith in it. On the contrary, philosophers like Hume and the logical posivitists would say that statements compatible with all states of affairs are nonsense and we should NOT believe them. If you can't prove a statement is false, that doesn't mean the statement is true or even more likely to be true. For example, I can't prove the universe didn't come into existence five minutes ago, complete with so-called "historical" records and so-called "memories". I can't prove we're not in the Matrix. But inability to prove something false doesn't mean it's true or even likely.
I'm sure you can see where this is going. The claim that spiritual substances (e.g., souls) exist looks to be compatible with all states of affairs, since by definition there is no possible empirical evidence for or against the existence of spiritual substances. So you can't prove that souls don't exist, but you can't prove invisible fairies don't exist either. Is there any difference between believing in souls and believing in other claims that are compatible with all states of affairs? And if we can't come up with a good argument for the existence of souls, what happens to the idea of personal immortality, which Christians believe to be immortality of soul? Is body all there is?
Most contemporary philosophers and psychologists are materialists, in the sense that they think there is only one world, the world explored by science, the world of res extensa. Most contemporary philosophers and psychologists explain thinking by saying material substances, e.g., brains, can think. They say it's fallacious (the fallacy of composition) to assume that because individual cells can't think, brains can't think. Remember John Searle's example? Just because no molecule of water is wet doesn't mean water isn't wet. What's true of the parts isn't necessarily true of the whole. Some properties — so-called emergent properties like wetness and thinking — are true of combinations of material substance (e.g., water), but false of the individual parts (e.g. water molecules). So most contemporary philosophers are dissatisfied with the sort of simple-minded hard behaviorist materialism of people like B. F. Skinner.
In this module, we explore alternatives to the substance dualist metaphysics of Descartes. We focus especially on pluralism, as illustrated in the metaphysics of Aristotle, and the 20th-century philosopher Gilbert Ryle.
This is the material for Quiz 7.
Readings for Quiz 7
The reading assignments for this section are:
Objectives for Quiz 7
You should be able to answer the following essay questions: