2008-2-PHI130.Week06

PHI130 Week 6: The Cartesian Revolution and Cartesian dualism

Lecture 11: The Cartesian Revolution

Modern philosophy begins in 17C with Rene Descartes (1596-1650) from France, and Francis Bacon (1561-1626) from England.

Plato wants to know about things that are unchanging in the world of forms. Descartes was interested in substantial things (corporeal things).

Descartes' ideas are still important and interesting today. Modern philosophy did not arise from these philosophers operating in a vacuum, there were other forces, and other thinkers of the time shared their ideas.

Modern philosophy is characterised by two gross ideas of rationalism and empiricism, and we'll look at Descartes as he is placed with respect to these concepts.

Modern philosophy is distinct from medieval philosophy before it, the latter being within the church framework, or scholasticism, who had to date had the resources to conduct philosophical inquiry. Modern philosophy is still interested in "what is real", just like prior philosophy. With Descartes and Bacon philosophy moved beyond "schools". Philosophy moved from the university and theory to the world, experiment and observation.

Bacon came slightly earlier than Descartes, and endeavoured to reconstruct the entirety of human knowledge, science, arts -- on the basis of experimentation and observation and induction. Bacon caught pneumonia conducting an experiment on a chicken in the snow and died. Bacon was interested in experimentation and induction, and also in about how we think about things.

Descartes was also likewise interested in how we think about things. Thinking about thinking as a way to know the world.

Bacon called common mistakes in thinking "idols of the mind", and he sought to improve our thinking by removing such errors. Such errors include:

• idols of the tribe, applicable to all individuals, such as jumping to conclusions and wishful thinking; errors of perception, careless or imprecise observations;
• idols of the cave, applicable to thinkers in a cultural context, including errors of authority, custom or opinion, favouritism among ideas and writers;
• idols of the marketplace, errors of our modes of communication, including errors in language;
• idols of the theatre, how grand superstitious or sophistic systems disrupt our ability to observe.

These are things to be overcome according to Bacon.

He recommends instead careful systematic observation. Look without bias at the world. Keep careful track of findings. Then you can know the world.

What makes Bacon and Descartes modern in contrast to medieval philosophers? They reject the scholastic view of harmony with the theology of the Christian church.

The new physical sciences become recognised as important. The mechanisms of nature don't have to suppose anything about God or scripture.

Also they really think that the human being has the resources to understand reality. They believe errors can be overcome and that we can get things right, i.e. arrive at true knowledge.

Neither Descartes nor Bacon were academic. Descartes a solider, and Bacon a public servant. They used the vulgar language, not the language of the theologians.

Modern philosophy becomes a secular enterprise that puts the individual, and the rational mind, at the centre of inquiry.

Kant sums up the modern philosophy as "dare to know". Not reliant on the tradition of the church or authority: think for yourself. This was a new concept at the time, though is largely embedded in contemporary culture today. It had political implications, such as in the French revolution. Emphasis on free expression, critical thinking, public debate. Leads to the rise of democracy.

Descartes: the father of modern philosophy.

Rationalism and empiricism: two strands in the early modern period. Classical division held rational and empirical as mutually exclusive, but this isn't how we tend to approach it these days as that's too simplistic. These stereotypes don't fit reality very well, but they are held to be useful frames for thinking.

Rationalism comes from Latin 'ratio', reason. That we can arrive at truth through logical implication independent of experience. E.g. nothing can be "red all over" and "green all over" at the same time. This can be known without experience.

Empiricism requires claims to knowledge to come from experience.

Rationalism emphasises mathematics and logical deduction.

Empiricism tends to reject a priori reason, and champions observation and induction or generalisation.

In these terms Descartes is the most celebrated rationalist. Why care about the distinction between common sense knowledge and other types of knowledge? Descartes says when you do philosophy you can't take things for granted or on authority. You want to think it through for yourself. Questions become difficult to answer with confidence in the face of radical doubt.

Cogito ergo sum: I think therefore I am, a slogan of Descartes'. Where does this idea come from? What's the point of this claim? We'll see this later, but it's why Descartes important. He sets up the project of radical doubt.

Descartes wants to be certain about the foundations for knowledge, especially in the context of the new heliocentric model of the universe, etc.

Descartes says if there's no secure foundation then we don't have stable or secure knowledge. He thinks if we can find a secure foundation then rationalism will lead to sound knowledge about reality.

Descartes meditations are recommended readings.

Descartes wants certainty. Descartes wants a "fixed point" to build reality on. He sets out to find this point of certainty. He sets out to show that we can guarantee or ground our knowledge with the right system. He's famous for his philosophical dualism.

Descartes' doubt: what's the motivation? Historically we see that we've made mistakes, and fell into the idols of the mind, and take things for granted, etc. Descartes embraces thinking, new science, radical doubt, and rejects tradition. He wants to be certain of the claims that he makes.

Descartes doesn't want to build on "unstable foundations". So he seeks one point from which to build his system. Descartes worries about being betrayed by his senses.

All Descartes requires to doubt something is to find that it might be false. I.e. it's not allowed if it can't be certain. You could be dreaming, or deceived.

Descartes is confident in the reality of numbers.

Descartes makes the "evil demon" argument. What if we've been deceived by our environment? Is there anything that can survive this level of scepticism? He won't accept "don't know, don't care".

He thinks that if you do his meditations you will come to know something.

Lecture 12: Cartesian Dualism

We've discussed modern philosophy, and suggested a look at meditation.

Today we look at the cogito argument and its mechanics.

The Meditations are a series of six exercises in thinking. Descartes says: begin by questioning everything that might not be certain. The meditations suggest how our knowledge can be grounded in certainty. His account of dualism helps to allow for this. I.e. that humans have both a mind and a body, mental and material, being two different kinds of thing.

You don't need any prior knowledge or expertise to be able to understand the meditations, and this reflects the foundations of modern philosophy: i.e. trust in human reason.

Descartes requires that you actually *do* the meditations, and actually *think* through the questions in the meditations.

Descartes published not only his ideas, but the rejections of his ideas and his rejoinder.

Descartes subjects all his knowledge to radical doubt so as to find his "Archemedian point", the point he can hold fixed: the cogito. He uses different phraseology than "cogito ergo sum".

He first doubts the senses. Anything could be a dream for instance. What about numbers or maths? Maybe these are secure against dreams, but the malicious demon argument causes us to doubt even observations of number (i.e. counting).

Descartes regards everything as potentially spurious. But at that point he still knows that he is thinking. This is held to be true knowledge, even in the face of the demon's deception...

Some objections and assumptions:

• Descartes says that if we can show that our most basic beliefs are open to doubt then everything is open to doubt. But just because some of our perceptions might lead to falsehood, not all necessarily do. Instead of a 'pyramid' structure, a 'raft' structure of planks, where some planks can fail independently of the whole. According to some thinkers this is what scientific knowledge has to be like: we're always at sea. We can't build the best raft before joining the sea. This is the coherence view of knowledge. The cogito requires the robust foundation as all ideas are to be integrated and interdependent.

• Is it valid to conclude that there is a substantial "I" on the basis of the experience of thought. There are other ways to think about this. Why does thinking require a thinker? Russell questions the substantial "I". Can there be a grin without a cat? A grin isn't a thing in itself, you can't have properties without substance. Thought implies a thinker.

• Why should it be thinking that does all the work? Why is thinking the basis of the mind/body dualism? Why can't we say I'm pacing up and down therefore I exist? Descartes says you could dream about that and find you were wrong, but thinking exists even in dreams.

If we accept the cogito, this leads to the question what is this "I" that exists? What do we really know about this "I" that exists? This is Descartes next project, where he sets up the arguments for mind/body dualism.

What am I? A philosopher, an Australian, a human being. These give rise to new questions. What is a rational animal? Descartes wants the fundamental derived from experience: what about the body? We have bodies. The body could be a dream. What about the thinking? Without the body the brain goes, and there will be no thinking. Descartes gets around this by believing that thinking can happen without the body. Thought is what we have. The "I" is defined as the thinking thing, as the activity of thinking. The real Descartes is his mind.

I exist. What am I? I have a body? Doubtful. Thinking alone is acceptable. I am, in the strictest sense, only a thing that thinks.

I think. If I cease thinking I might cease to exist. What about unconsciousness? Do we cease to exist if we're unconscious? Do we drop out of existence when we're unconscious. Descartes doesn't worry about this, he believes that mental activity occurs even in the unconscious. Descartes integrates thinking with identity.

Descartes knows only that he is a thinking thing. That what he is, is only his mind, and not his body. The body could go. Is Descartes allowed to draw this conclusion? The parallel argument: what's in the punch? Your friend says "I know only that it contains orange juice". Does this mean that it contains only orange juice? No.

Descartes says our essential nature is only the mind. Descartes' reason leads to this "weird" point. He compares sense things (i.e. wax) with knowledge of his own mind. He looks at dry and melted wax and observes variation in the properties of the wax. This means that sensory observation can't tell him that it's the same wax. If it's still the same wax the senses haven't been able to determine that, it's the mind that has been able to determine that it's the same wax. The mind grasps the wax as purely extended stuff. This reinforces the notion that "I" (the thinker) exist.

How does one know that other people have minds? Only talking, faces, etc., can be observed. Thinking can't be observed. Descartes says that judgement, or reason, tells us of the existence of other minds. Other people could be zombies. Descartes wants to know that other people exist. How can we know this important thing? Not by physical sensory observations. To know others exist we have to use our minds. It's not the body or what we sense of it that tells us that other people are out there.

In the case of the mind we need to go beyond the physical to know about other minds. Knowing identity is not the same as knowing nature. Identity requires spatiotemporal continuity, but this doesn't answer questions regarding nature.

Descartes wants to say that the mind is better known than the body, and he uses this to draw the dualist conclusion: that the body is distinct from the mind. The "I" knows itself better through reflection than sensing.

Descartes concludes that we have two types of things: the body extended in space, and the mind doing the thinking. It's the mind or the intellect that understands or reflects on itself, and gets to know itself. To really exist is to have reflexive thought, "thinking about thinking", this self-consciousness grounds us in reality.

Reading Questions

J Cottingham

  1. What metaphor does Francis Bacon use to describe rationalists and empiricists?

Empiricists as ants that collect and use, and rationalists who spin webs out of themselves.

TFTD: The spider's web has a use.

  2. What are the different bases for the philosophical systems of rationalists and empiricists?

Rationalists ground reality in the mind and reason, whereas empiricists ground reality in experience and observation. Rationalists deduct from principles, empiricists induct or generalise from observation.

  3. Why is the 'armchair theorizer' view of rationalists a caricature?

Because rationalist knowledge is not grounded in experience.

  4. What are the origins of the words 'rationalist' and 'empiricist'?

Rationalist, from the latin 'ratio', meaning reason or relation. Empiricist from the Greek 'emperia', meaning 'experience'.

  5. How did Galileo sum up the new creed of modern philosophy?

That nature could only be understood through mathematics.

  6. Explain four strands of rationalism.

Descartes, 2nd Meditation from Meditations

  1. What is Descartes looking for? How is his project like Archimedes'?
  2. What will he suppose about his memory and senses? What does he convince himself about the external world?
  3. What indubitable point does Descartes reach? How does the idea of a deceitful demon help him reach this conclusion?
  4. What does Descartes understand his body to be like?
  5. What does Descartes conclude that he is like?
  6. Why does Descartes consider the piece of wax?
  7. What does he conclude about the information given to him by his senses?
  8. How does Descartes conclude that the wax is revealed by the mind alone?
  9. What does Descartes conclude from seeing the people across the road?
 10. What overall conclusions does Descartes draw about his mind?