Think: A Compelling Introduction to Philosophy

by Simon Blackburn

So after considering everything very thoroughly, I must finally conclude that this proposition, I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind. This is the famous ‘Cogito, ergo sum’: ‘I think, therefore I am.’

An argument is valid when there is no way—meaning no possible way—that the premises, or starting points, could be true without the conclusion being true (we explore this further in Chapter 6). It is sound if it is valid and it has true premises, in which case its conclusion is true as well.

The senses sometimes deceive us. We cannot distinguish occasions when they do from ones when they do not. So for all we know, any particular sense experience maybe deceiving us.

I cannot doubt that I am here in the room. I can doubt whether a person who will get bad news tomorrow is in the room. Therefore, I am not a person who will get bad news tomorrow. A nice proof with a welcome result! The fallacy is often called the ‘masked man fallacy’: I know who my father is; I do not know who the masked man is; so, my father is not the masked man.

Causation is like passing the baton in a relay race. So, for example, it takes heat to make something hot, or movement to induce motion.

So an idea of infinity, for instance, would be an infinite idea. (Would an idea of something solid be a solid idea?) Similarly an idea of perfection would be a perfect idea, and would require a perfect cause.

One way of thinking—Hume’s own—accepts the view that our system of belief needs some kind of foundation. However, it denies that that foundation could have the kind of rational status that Descartes wanted. The veracity (truthfulness) of our senses and reasonings is itself part of the foundation. It cannot itself be demonstrated by standing on some other ‘original principle

The emphasis on natural ways of forming belief chimes in with another strand in Hume and other British philosophers of the seventeenth and eighteenth centuries, which is their distrust of the power of unaided reason. For these philosophers, the best contact between mind and the world is not the point at which a mathematical proof crystallizes, but the point at which you see and touch a familiar object. Their paradigm was knowledge by sense experience rather than by reason. Because of this, they are labelled empiricists, whereas Descartes is a card-carrying rationalist.

And soon we visit an area where the champion of British empiricism, John Locke (1632–1704), is as rationalist as the best of them. Great philosophers have a disturbing habit of resisting labelling.

On this story, the true moral of Descartes’s struggles is that if we raise the question whether our experience and reasoning (en bloc) accords with the way the world is (en bloc), it will take an act of faith to settle it.

‘God’ simply labels whatever it is that ensures this harmony between belief and the world.

If our eyesight, for example, did not inform us of predators, food, or mates just when predators, food, and mates are about, it would be of no use to us. So it is built to get these things right. The harmony between our minds and the world is due to the fact that the world is responsible for our minds.

A rather different response shrugs off the need for any kind of ‘foundations’, whether certified by reason, as Descartes hoped, or merely natural, as in Hume. This approach goes back to emphasizing instead the coherent structure of our everyday system of beliefs: the way they hang together, whereas the sporadic experiences or beliefs we get in dreams are fragmentary and incoherent.

It then points out an interesting feature of coherent structures, namely that they do not need foundations. A ship or a web may be made up of a tissue of interconnecting parts, and it derives its strength from just those interconnections. It does not need a ‘base’ or a ‘starting point’ or ‘foundation’.

It is good, then, to remember four options in epistemology (the theory of knowledge). There is rational foundationalism, as attempted by Descartes. There is natural foundationalism, as attempted in Hume. There is coherentism. And brooding over all of them, there is scepticism, or the view that there is no knowledge.

For Descartes it is not only that mental events are distinct from physical events. They also belong to a distinct kind of substance—immaterial substance—a kind of ghost-stuff or ectoplasm.

Strictly speaking if I say, ‘I’ thought of the Queen and I saluted,’ there is a kind of ambiguity: the ‘I’ that is the subject of the thought is not the ‘I’, the body, that salutes. Thoughts and experiences are modifications in one kind of stuff; movement and position belongs to the other. This part of Descartes’s doctrine marks him as a ‘substance dualist’. It is not just that there are two kinds of properties (mental properties and physical properties) and that persons can have both. It is that there are two kinds of bearers of properties as well. Of course this is theologically convenient: it opens the way to the immortality of the soul,

The argument is that if mind and matter are thought of in the Cartesian way, then there would be wide-open possibilities of a bizarre kind, about which we could know nothing. So, since this is intolerable, we should rethink the conception of how things are (this is called the metaphysics). A better conception of mind and its place in nature should foreclose these possibilities.

You could believe everyone is a mutant or zombie

On this account, the way forward is to reject the picture of mind and body given to us by Cartesian dualism. And we should be encouraged to reject Cartesian dualism by metaphysical as well as epistemological pressures.

Locke, on the other hand, thinks that God has two different things to do. First, fix all the physics and laws of physics. But second, decide how to ‘annex’ mental events to physical events, fixing up psycho-physical relations. It is as if the world has two different biographies, one of its physical happenings and one of its mental happenings, and God had to decide how to relate them.

In the philosophy of mind the Leibnizian must deny the possibility of Zombies and Mutants. If the physical biography is fixed, then the mental biography is fixed thereby. There is no independent variation, actual or possible. The philosophical problem is that of understanding why this is so.

Locke thought he could leave it open whether it is an immaterial ‘thing’ (a ghost) within us that does the thinking, or whether it is the physical system itself, since God can superadd thought to anything he likes. But he is abundantly clear that it takes a mind to make a mind. It takes a special dispensation: thought cannot arise naturally (or, as Leibniz has it, in a rationally explicable way) from matter. For unthinking particles of matter, however put together, can have nothing thereby added to them, but a new relation of position, which it is impossible should give thought and knowledge to them.

There are even philosophers who think that some kind of Cartesian dualism is true, and that the mind really is epiphenomenal—never causes any physical events at all. They say this because they recognize that the physical is a closed system. If there is a process that begins with a pin being stuck in you and ends with a wince, then there is an entire physical chain from pin to wince that explains the wince. So, they think, it has to be false that you wince because you are in pain.

This bit of common sense has to be given up. You wince because of the physical pathways, not because of a mental add-on. These thinkers are in fact stuck with the same problem of interaction that faces Locke.

The point is that if we can analyse mental ascriptions in physical terms, then the Leibnizian dream of a rational or a priori way of seeing how the physical gives rise to the mental is vindicated.

Pain is a mental event or state that lends itself fairly readily to the project of analysis, for at least it has a fairly distinctive, natural, expression in behaviour. Other states with the same kind of natural expression might include emotions (sadness, fear, anger, and joy all have typical manifestations in behaviour). But other mental states only relate to behaviour very indirectly: consider the taste of coffee, for example.

There is something that it is like for us to taste coffee (not for Zombies). But it doesn’t typically make us do anything much. Contemporary thinkers like to put this by saying that there are qualia or raw feels or sensations associated with tasting coffee.

Wittgenstein tried to show that there could be no significant thought about the nature of one’s past (or future) mental life if that mental life is divorced from the physical world in the way that Cartesian dualism proposes. It becomes, as it were, too slippery or ghostly even to be an object of our own memories or intentions.

The Leibnizian idea is that if I and my twin (which now might be myself as I was yesterday) are functioning physically in the same way, then there is no possibility that our mental lives are different. How can we flesh out this suggestion? Here is a sketch of an answer.

Brown is darkened yellow, but for him yellow is already dark. So it is difficult to imagine how his physical discriminations could match mine, given this complete disparity in mental experience. In short, the possibility becomes a good deal less clear, and we may feel our way to denying that it is a possibility at all.

We would be engineering a conception of the mind that closes the gap between the physical and the mental, that is, between the fully functioning and responsive visual system in the brain and the apparently superadded ‘subjective’ qualia of colour experience. Such a piece of engineering would be a vindication of Leibniz’s position. Subjective colour experience becomes not just a queer addon, but the inevitable, rationally explicable, expression of the kinds of physical functioning of the creatures that we are.

Probably the right reaction to this is to deny that thoughts are things at all. The mistake of supposing that to every noun there corresponds a ‘thing’ is sometimes called the mistake of reification.

The last chapter had us thinking about what the brain produces: elements of consciousness such as thoughts, or sensations, or qualia. But when we think about ourselves, we are conscious of other things as well. We don’t only register the world, as we take it to be. We act in it.

Freedom brings responsibility, and people who abuse it deserve blame and punishment. But nobody deserves punishment for failing to do something if they could not do it. It would be most unjust to punish me for not having gone to the Moon, or to punish a man in prison for not keeping an appointment outside the prison, for example.

Here the obstacles are beyond the agent’s control. That means, he or she is not to blame.

Lucretius and the young man at the beginning of the chapter can be given an argument: The past controls the present and future. You can’t control the past. Also, you can’t control the way the past controls the present and future. So, you can’t control the present and future.

The first premise of this argument is a thumbnail version of the doctrine known as determinism, which can be put by saying that every event is the upshot of antecedent causes.

People who accept this argument are called hard determinists, or incompatibilists, since they think that freedom and determinism are incompatible.

We might be optimistic about doing this, because the best current science of nature, quantum physics, is standardly interpreted as postulating uncaused events. In the quantum world, there are microphysical events that ‘just happen’.

If anything, physical indeterminism makes responsibility and the justice of blame even more elusive. This is sometimes called the dilemma of determinism. If determinism holds, we lose freedom and responsibility. If determinism does not hold, but some events ‘just happen,’ and then, equally, we lose freedom and responsibility.

unfolded. My consciousness reveals my freedom to me.

In this parable, the water is not conscious of the causal setups necessary for it to boil, make waves, and so on. It only remembers that it sometimes does these things. Hence, it thinks, it can do them. So it attributes its calm to its own voluntary decision. But in this it is mistaken: if it ‘tries’ to boil when the temperature is wrong, or ‘tries’ to make waves when there is no wind, it will soon discover that these things do not depend on its own decision.

To make the same point, Wittgenstein imagines the leaf falling in the autumn winds, and saying to itself, ‘Now I’ll go this way, now I’ll go that.’

The Real Me sits in the control room, and the whole person behaves freely when it is in command. If it is not in command, the brain and body get on with their (‘mindless’) physical evolutions. This is mind-body dualism again. The Real You dictates events. Messages come in, perhaps through the pineal gland. A breath of soul then fans neurones and synapses into action, and initiate new causal chains. There is a ghost in the machine, and the machine behaves freely when the ghost is in charge.

Dualism tries to understand human freedom by introducing an extra ingredient, the controlling soul. But how do we understand the freedom of the soul?

And of course there is the whole problem of mind-brain interaction, which is so intractable given Cartesian dualism. The physical system is a closed system. It takes a physical cause to produce a physical effect.

Schoolteachers sometimes say things like this: ‘I don’t mind a stupid pupil, but I do dislike a lazy one.’ In the grip of the hard determinist argument, you might think that this is just prejudice: some people are born stupid and pitied for it; why should those born lazy not be similarly pitied for that? It is just tough luck, either way. But the schoolteacher’s attitude will have a point if laziness responds to incentives in a way that stupidity does not. If respect for the teacher’s opinion can make you work harder, whereas it cannot make you smarter, then there is one justification for the asymmetry. The teacher is in the business of resetting your evaluating module.

We have here the beginning—but only the beginning—of the programme of compatibilism, or the attempt to show that, properly understood, there is no inconsistency between acknowledging determinism and our practices of holding people responsible for their actions.

To get at the right sense of ‘could have done otherwise’, we might offer what I shall call the first compatibilist definition: A subject acted freely if she could have done otherwise in the right sense. The subject could have done otherwise in this sense provided she would have done otherwise if she had chosen differently. And, says the compatibilist, that is all that is needed to justify our reactions of holding people responsible, and perhaps reacting to them with blame and anger.

The ghostly response to determinism posited a kind of intervention from outside the realm of nature: a ‘contra-causal’ freedom, in which the ghost is distinct from the causal order of nature, yet mysteriously able to alter that order. We could call that conception, interventionist control. It is sometimes known in the literature as a libertarian conception of freedom,