Philosophy
Page 8
Is there anything you can truly claim to know under these circumstances? You know nothing about your body, your history or your world. It seems as though you can’t be certain of anything at all.
Descartes discovered, however, that there is one thing of which you can be certain, even as a brain in a vat. He discovered it by thinking about thinking.
In order to think – even if all your thoughts are all falsehoods – you have to exist. Therefore you can be absolutely certain of your own existence.
This discovery is called the cogito, short for the Latin phrase cogito ergo sum, which means ‘I think therefore I am’. It is still today regarded as one of the most indisputable proofs ever invented. But is it enough?
Thinking is another attribute of the soul; and here I discover what properly belongs to myself. This alone is inseparable from me. I am – I exist: this is certain; but how often? As often as I think; for perhaps it would even happen, if I should wholly cease to think, that I should at the same time altogether cease to be. I now admit nothing that is not necessarily true. I am therefore, precisely speaking, only a thinking thing, that is, a mind (mens sive animus), understanding, or reason, terms whose signification was before unknown to me. I am, however, a real thing, and really existent; but what thing? The answer was, a thinking thing.
Descartes, Meditation II, Meditations on First Philosophy (http://oregonstate.edu/instruct/phl302/texts/descartes/meditations/Meditation2.html)
Spotlight
Descartes walks into a bar. The bartender walks up to him and says, ‘Would you care for a drink?’ Descartes replies, ‘I think not,’ and disappears.
God and the world
If we were to stop with the cogito we would be condemned to solipsism – the view that only the self exists. Take a moment right now to try this view out.
Feeling a little lonely? So did Descartes. He resolved to build on his gains, continuing in the following way:
1 So, I know for certain that I am a thinking thing. What shall I think about? The best thing I can think of is God.
2 God is a being far superior to me. In fact, he is infinite. How did I think of him? If I am the only being in existence, then I must have made up the idea of God all by myself. But I am finite. Surely, it’s impossible for a finite being to think of an infinite being. Therefore I am not alone after all – another being, an infinite being, must exist.
3 Perhaps the malignant demon gave me the idea of God. But God is infinitely good and not at all malignant. A malignant demon – whether he is finite or infinite – could not have conceived of infinite goodness.
4 One might suppose that I or the malignant demon could conceive of God by negation. If I’m hungry, then I can think of being full, and, if I’m tired, then I can think of being awake. Therefore if I think of my limitations, then I can think of limitlessness.
5 But the idea I generate by negating my own limitations is not the same as the idea I have of God. The idea I have of God is such a clear and distinct idea of infinite perfection that it could not have come from anything but a being that is infinitely perfect.
6 Therefore, an infinitely perfect being must exist.
7 Could this infinitely perfect being be my malignant demon? That is, could God himself be systematically deceiving me about the world?
8 Surely not, because an infinitely perfect being is all good. Granted, an all-good being could allow careless thinkers to be deceived by their own carelessness. But he could never allow someone who is trying to be a careful thinker to be continuously and completely deceived. Much less could he deliberately cause such deception.
9 Therefore the world must exist.
Hey presto! – starting with just his own existence, Descartes quickly restores the reality he believed in before beginning his meditation. He has learned that, if he thinks carelessly, he may come to false conclusions about the world. But if he uses reason, striving always for the standard of ‘clear and distinct’ ideas, he should be able to attain new knowledge.
Granting that Descartes’s method of doubt succeeds in proving the existence of the self, is it equally successful in proving the existence of God and the world?
The Cartesian circle
Descartes’s proof of God and the world relies crucially on the notion of the ‘clear and distinct idea’. His reasoning can be summarized as follows:
1 I have a clear and distinct idea of God.
2 My idea of God is so clear and distinct that it must have come from God.
3 Therefore God must exist.
This way of interpreting Descartes’s argument shows that it suffers from the same problem as Anselm’s ontological proof, which we saw in the last chapter: it appears to be circular because it assumes the very thing it’s trying to prove.
Descartes makes a distinction between two different kinds of ideas – those that are clear and distinct versus those that are vague and hazy. He further claims that the clear and distinct ideas are guaranteed to be true. What could possibly secure this guarantee other than God? Conversely, if God doesn’t exist, there’s no guarantee that clear and distinct ideas are true.
What’s to stop our malignant demon from transmitting two different types of falsehood to us – those that seem clear and distinct as well as those that seem vague and hazy? Presumably, being so powerful, he could do this just as easily as you are able to speak loudly or mumble softly. Evidently, Descartes’s proof is not immune to his own method of doubt.
Although Descartes and his followers can develop a response to this criticism, it will be a challenge for them to reach their goal of restoring reality.
Dualism
Descartes’s proof of God and the world was never as enthusiastically received as the cogito itself. In facing down the malignant demon, Descartes shows that, while we can doubt the existence of our bodies, we cannot doubt the existence of our minds. This seems to support the metaphysical view known as dualism, according to which human beings are composed of two different kinds of substance: physical and mental.
The physical aspect of the human being includes everything that can be empirically observed, and so, of course, it includes the brain. The mental aspect includes the thoughts and feelings that can be observed only introspectively, where introspection is understood as a self-reflexive examination of one’s own consciousness.
Dualists believe the brain alone is insufficient to explain all our thoughts and feelings. In their view, our consciousness, while connected to the brain, goes beyond its capacity. Dualists sometimes call this mental aspect ‘mind’ and sometimes ‘soul’, treating the two terms as synonymous.
Of course, the idea that each human being possesses a soul has a long history in many religions. Descartes himself was at least nominally a member of the Catholic Church, which holds that the soul survives the death of the body. Anyone who wants eternal life will have to believe in a non-physical aspect of themselves.
But wanting eternal life is not a good reason for believing in the existence of the soul. After all, no matter how badly children want presents to appear in the Christmas stockings they hang, they cannot thereby make Santa Claus real. The truth is that ordinary mums and dads are sufficient to explain all the gifts that have ever appeared in Christmas stockings.
Is the brain alone sufficient to explain all our thoughts and feelings? If so, there is no reason to believe in the soul.
Spotlight
According to Descartes’s dualism, the body is a machine controlled by the soul. Since animals don’t have souls in his view, they are pure machines, incapable of feeling pain. They cry out when you strike them, but only in the same way that a musical instrument sounds when struck. Descartes is said to have tested this theory by practising vivisection (live dissection) on cats – or perhaps he was just getting his revenge against cats because a cat had bitten off his little toe when he was a child.
Qualia
Dualists argue that there is something very significant that the brain alone is insufficie
nt to account for – namely, qualia.
Suppose I place you in a futuristic CAT scan and ask you to think of your lover. I can observe the neurons firing in your brain. I can measure how your brain chemistry changes. Perhaps I can even simulate the same changes in my own brain. Nevertheless, I cannot observe your love. No matter how sophisticated my instruments are, I will never know what your love feels like introspectively.
This subjective conscious experience – what your love feels like – is a quale. Our minds are full of qualia, from something as simple as how cinnamon smells to something as complex as what it’s like to perform a triple axel. A complete scientific description of these phenomena from the outside does not capture what they are from the inside. Hence, it seems that our minds must be something more than just brains.
Nevertheless, there is a real mystery concerning how mental substance could be connected to physical substance. Descartes’s critics say that his view makes human beings look like ‘a ghost in a machine’ because the soul is supposed to control the body the way a person drives a car. But how can a ghost push or pull the buttons and levers to make a machine move? Without any physical substance, its hands would go right through the controls!
Likewise, how does the soul move the body? We know how neurons stimulate muscles to contract and propel our bodies through space. But how would something non-physical in turn stimulate a neuron? Dualists want to say that your love can make you do something – such as bake a birthday cake. How will your soul cause your body to take action? This is known as the mind–body problem.
In Descartes’s day, the function of the pineal gland was unknown. Descartes therefore hypothesized that it could be the seat of some kind of transference between mental and physical substance. Now that we know the function of the pineal gland, however, this hypothesis is no longer taken seriously.
Case study: materialism
Materialism, the view that human beings are purely physical bodies, has grown increasingly popular since Descartes’s day. One of its most vocal exponents is the American philosopher Paul Churchland (1942– ), who maintains that qualia do not exist.
According to Churchland, the mistaken belief in qualia is a product of common language. Because people regularly talk about how they feel ‘on the inside’, it seems that these feelings have objective existence.
By analogy, consider a society of people who believe in witches. They talk about witches all the time and think they observe witchery playing an active role in the world. It would be hard to convince these people that their witch concept is nothing but ‘folk psychology’ – a primitive and inaccurate explanation. Churchland writes:
Modern theories of mental dysfunction led to the elimination of witches from our serious ontology. The concepts of folk psychology – belief, desire, fear, sensation, pain, joy, and so on – await a similar fate, according to the view at issue. And when neuroscience has matured to the point where the poverty of our current conceptions is apparent to everyone, and the superiority of the new framework is established, we shall then be able to set about reconceiving our internal states and activities, within a truly adequate conceptual framework at last. Our explanations of one another’s behaviour will appeal to such things as our neuropharmacological states, the neural activity in specialized anatomical areas, and whatever other states are deemed relevant by the new theory.
Paul Churchland, Matter and Consciousness (MIT Press, 1999), pp. 44–5
Notice that Churchland’s list of folk psychology concepts does not include love. Will neuroscience one day make it possible for us to eliminate all talk of love? Would this be a good thing, or would it be good to continue to speak of love even if it doesn’t really exist?
Dualists continue to look for the connection between mind and body elsewhere, such as in the mysterious properties of quantum mechanics. As science progresses, many of these hypotheses, like the pineal gland hypothesis, will be ruled out – but perhaps not all. It remains to be seen whether science will ever be able to provide a fully adequate account of our thoughts and feelings.
Key ideas
The cogito: Descartes’s proof of his own existence
Dualism: The view that human beings are composed of two substances: body and soul
Folk psychology: A primitive and inaccurate explanation
Introspection: A self-reflexive examination of one’s own consciousness
Materialism: The view that human beings are purely physical bodies and that there is no such thing as the soul
Mind–body problem: The mystery concerning how the mental substance could be connected to physical substance
Qualia: Instances of subjective, conscious experience
Rationalism: The view that we discover innate truths through the power of clear thinking
Solipsism: The view that only the self exists
Fact-check
1 Descartes’s rationalism developed from which of the following?
a Materialism
b Innatism
c Empiricism
d Solipsism
2 What is the purpose of Descartes’s malignant demon?
a To question eternal life
b To see whether anything is certain
c To prove that the soul is folk psychology
d To promote meditation
3 Which of the following is a problem with Descartes’s argument for the existence of God?
a It seems circular
b It seems vague
c It seems hazy
d It seems malignant
4 Descartes concludes that God must exist because he is which of the following?
a Loving
b Limitless
c Infinite
d Eternal
5 Which of the following best represents the soul and the body according to Descartes?
a God and a demon
b A caterpillar and its cocoon
c Two lovers
d A captain and his ship
6 Which of the following is an example of folk psychology?
a Neurons
b Demons
c Qualia
d Dreams
7 Which of the following best demonstrates the mind–body problem?
a A demon playing tricks
b A witch casting spells
c A ghost walking through walls
d A cat howling in pain
8 Which of the following would deny that human beings have life after death?
a Churchland
b Descartes
c Plato
d Anselm
9 Someone who believes in only their own existence is which of the following?
a A materialist
b A rationalist
c A solipsist
d An innatist
10 What is the first thing Descartes is able to prove against the malignant demon?
a That he exists
b That God exists
c That the world exists
d That the malignant demon exists
Dig deeper
Steven M. Duncan, The Proof of the External World: Cartesian Theism and the Possibility of Knowledge (James Clarke & Co., 2008)
Tom Sorell, Descartes: A Very Short Introduction (Oxford, 2001)
Bernard Williams, Descartes: The Project of Pure Enquiry (Routledge, 2005)
6
Hobbes and freedom
‘The condition of man: war of everyone against everyone.’
Thomas Hobbes
In this chapter you will learn:
• the meaning of free will
• why determinists reject free will
• how Hobbes explains human choices
• how compatibilism attempts to save a measure of human freedom
• the meaning of the state of nature
• why Hobbes thinks we need an absolute sovereign
• why Rousseau favours a republic over an absolute sovereign
• about social contract theory and how the v
eil of ignorance supports it.
Thought experiment: change your life?
You are window shopping in China Town. The evening air is cool and breezy. The pavement is strewn with festive lights. From each door you pass wafts a new flavour, from musky incense, to fresh fish, to sweet-and-sour chicken.
Ahead you see a shrunken, wrinkled Chinese woman with a basket. As you approach, she holds up a fortune cookie and smiles toothlessly at you.
‘You buy?’ she asks.
You hesitate and pat your pocket absently for spare change. You actually wouldn’t mind buying a fortune cookie. On the other hand, you don’t feel like stopping to dig your wallet out of your backpack.
You smile and shake your head. ‘No thank you.’
The woman’s eyes grow wide and she stops smiling. ‘Could change your life!’
You sigh and begin reaching for your backpack.
As you shrug its strap off your shoulders, you catch the scent of fresh pastries. It seems to be coming from a bakery across the street.
You turn away from the woman, shaking your head firmly this time.
She puts her hand out to keep you from leaving, but you angle around her, stepping off the narrow pavement into the street.
A deafening screech of tyres whips your head around just in time to feel the cold, hard front of a bus slam into your face.
For an instant, you feel excruciating pain.
Then nothing.
You are looking at the Chinese woman again – just her face, surrounded by darkness. Without speaking, she somehow communicates the following message to you.
‘You are in limbo. Having been hit by a bus, you are on your way to the world of the dead. It’s not too late, however, to turn back the clock and change your life. If you go back to the moment at which you were trying to decide whether or not to buy a fortune cookie and make the opposite choice this time, you will live instead of die.’