PH2206GEK, Founders of Modern

Lecture 1

Modern European Philosophy:

Rationalism Versus Empiricism

Assoc. Prof. John Holbo

phihjc@nus.edu.sg

Warning:

‘Modern’ means different things to different people.

Modern history

Modern art

Modern rock

Modern life

Modern love

Modernity

Postmodernity

Modern, modern, modern, modern. Say it too many times, the word starts to lose all meaning.

René Descartes (1596-1650)Discourse on the Method (1637)Meditations on First Philosophy (1641)

Baruch (or Bernard) Spinoza (1634-1677)Tractatus Theologico-Politicus (1670)Ethics (1673)

John Locke (1632-1704)Essay Concerning Human Understanding (1690)

Gottfried Leibniz (1646-1716)Discourse on Metaphysics (1686)Monadology (1714)

George Berkeley (1685-1753)A Treatise Concerning the Principles of Human Knowledge (1710)Three Dialogues between Hylas and Philonous (1713)

David Hume (1711-1776)Treatise of Human Nature (1739)An Enquiry Concerning Human Understanding (1748)

Immanuel Kant (1724-1804)Critique of Pure Reason (1781)Prolegomena to Any Future Metaphysics (1783)

Descartes (1641)

Locke (1689)

Berkeley (1710)

Hume (1739)

Spinoza (1665)

Leibniz (1685)

Kant

Empiricism

RationalismModern European

Philosophy

I. Presocratic Philosophy 600-500 BC

II. Golden Age of Greek Philosophy: 450-350 BC: Plato & Aristotle

III. Hellenistic Philosophy: 300 BC - 300 AD

IV. Early Christian Philosophy): 300-450 AD: Augustine

V. The Dark Ages 400-800 AD

VI. Late Medieval Philosophy: 800-1100 AD

VII. High Medieval Philosophy 1100-1350 AD: Aquinas

VIII. Renaissance Philosophy 1350-1550

IX. Modern Philosophy 1550-1870 AD: Descartes

1 What is the nature of the human subject (the mind)? [Philosophy of Mind]

2 What is the nature of the world (matter)? [Metaphysics]

3 What is the nature of the relation between mind and matter, such that the former can know the latter? [Epistemology]

4 What is the nature of science? [Philosophy of Science]

We can think of the history of modern philosophy (conventionally conceived) as focusing on four basic questions (and note how much this leaves out, by the by -- ethics, politics and so forth):

Science is highly esteemed. Apparently it is a widely held belief that there is something special about science and its methods. The naming of some claim or line of reasoning or piece of research “scientific” is done in a way that is intended to imply some kind of merit or special kind of reliability. But what, if anything, is so special about science? What is this “scientific method” that allegedly leads to especially meritorious or reliable results?

- A.F. Chalmers, What Is This Thing Called Science?

The first thing you might think to say about the claims is that they are special because they are TRUE.

But whatever else may be wrong with this, it isn’t sufficient.

Socrates: the trouble with true belief is that it may ‘run away’ unless tied down with ‘threads of memory’.

Do not show me a general who is good. I want one who is lucky.

- Napoleon

Do not show me a scientist who is good. I want one who is lucky.

- Napoleon

Try again: what makes the claims of science special is that they are KNOWLEDGE. (Other stuff is just BELIEF or FAITH. It may be true, but that will just be luck.)

But what is knowledge? How do you define it? How can you tell whether you’ve got it?

What a man believes, he thinks he knows. - Aristotle

Knowledge = df. justified, true belief.

… but what does ‘justified’ mean?

We proceed to the next key words from the Chalmers passage: line of reasoning; piece of research.

Descartes defines knowledge in terms of doubt. While distinguishing rigorous knowledge (scientia) and lesser grades of conviction (persuasio), Descartes writes …

http://plato.stanford.edu/entries/descartes-epistemology/#1.1

I distinguish the two as follows: there is conviction when there remains some reason which might lead us to doubt, but knowledge is conviction based on a reason so strong that it can never be shaken by any stronger reason.

- Descartes

Knowledge implies CERTAINTY. (If Descartes is right.)

But this is ambiguous between a psychological and a justificatory sense.

I can be certain due to overconfidence. If I’m overconfident, we think that’s almost the OPPOSITE of knowing.

We want certainty in the sense of justification.

Also, certainty seems too strong …

Descartes’ Method:

1. Never accept anything doubtful.

2. Divide each difficulty into as many parts as possible.

3. Conduct my thought in an orderly way.

4. Make complete enumerations and general reviews.

Like the precepts of some chemist; take what you need and do what you should, and you will get what you want.

- G. W. Leibniz

But Descartes’ method isn’t common sense, and it doesn’t sound like chemistry or any other science either.

That first step is a doozy:

Never accept anything doubtful.

1) Science is collaborative. Even if you work by yourself, you consult the works of others. That requires a degree of trust. Trust is incompatible with doubting everything.

2) Science is fallible. Every good scientist knows that any result may be overturned tomorrow by further evidence.

2) Science is (bit hard to know which term is best) hypothetical. (Or maybe: probabilistic.) This means it doesn’t wait around for absolute certainty to arrive before it moves along.

Why is science fallible and hypothetical (never mind about collaborative)?

Chalmers suggests we have an intuition that something like the following might be right:

What is so special about science is that it is derived from the facts, rather than being based on personal opinion.

Science is fallible and hypothetical because pesky new facts may pop up to bother us.

How could Descartes (and Leibniz) get so confused as even to suggest the contrary?

Let’s start like so: Chalmers goes on to suggest that ‘derived from the fact rather than personal opinions’ is a very problematic formula. Let me approach Descartes by bringing out how so …

How can it be that mathematics, being after all a product of human thought independent of existence, is so admirably adapted to the objects of reality?

- A. Einstein

Here’s an EPISTEMOLOGICAL thought. A thought about the nature of knowledge - about the relation between mind and reality.

Why does this make trouble for ‘facts rather than opinions’ as a formula for science? Let’s jump back to 1596 …

Let’s read a bit from …

Johannes Kepler, Mysterium Cosmographicum: A Prodromus to Cosmographical Treatises, containing the Cosmic Mystery of the admirable proportions between the Heavenly Orbits and the true and proper reasons for their Numbers, Magnitudes and Periodic Motions.

Why waste words? Geometry existed before the Creation, is co-eternal with the mind of God, is God himself (what exists in God that is not God himself?); geometry provided God with a model for the Creation and was implanted into man, together with God’s own likeness - and not merely conveyed to his mind through the eyes.

…These figures pleased me because they are quantities, that is, something which existed before the skies. For quantities were created at the beginning, together with substance; but the sky was only created on the second day …The ideas of quantities have been and are in God from eternity, they are God himself; they are therefore also present as archetypes in all minds created in God’s likeness. On this point both the pagan philosophers and the teachers of the Church agree.

In 1595, while inscribing the following geometrical figure on the board of his classroom, Johannes Kepler was struck by an idea.

For years already, he had mulled a question, concerning the nature of the solar system. Why six planets, “instead of twenty or a hundred?”

6?5?

20?

100?

Looking at the lefthand figure on the blackboard one day, Kepler was struck that the ratios of the two circles were the same as the orbits of Saturn and Jupiter.

Saturn and Jupiter are the ‘first’ -- i.e. outermost -- planets, and the triangle is the ‘first’ figure in geometry. (Any figure with fewer sides is a line, after all.)

Next comes Mars. . .

Then Earth. . .

But wait: the universe is three dimensional, not two dimensional. Furthermore, there are five intervals between the planets, and five ‘Platonic’ solids. It must be that these figures will give us the ratio of the orbits.

Start with Saturn (and an orbital sphere of sufficient thickness)

Insert a cube within that sphere, and a sphere within that cube, within which Jupiter may safely spin. . .

Repeat procedure with a tetrahedron for Mars. . .

And a dodecahedron for Earth.

An icosahedron between Earth and Venus. . .

Between Venus and Mercury an Octahedron.

Add the sun. . . and we are done!

Within a few days everything fell into its place. I saw one symmetrical solid after the other fit so precisely between the appropriate orbits, that if a peasant were to ask you on what kind of hook the heavens are fastened so that they don’t fall down, it will be easy for thee to answer him. Farewell!

Except it was all totally wrong.

Kepler and Tycho - quarrelsome marriage of theory and observation.

In science there is only physics; everything else is stamp collecting. - Ernest Rutherford

But it took years before Tycho would let Kepler see his cool stamp collection [I mean his data set] so he could do some decent physics …

To make a long story short, Kepler went on to formulate his Three Laws of Planetary Motion:

1. The orbits of the planets are ellipses, with the sun at one focus.

2. A line joining a planet to the sun sweeps out equal areas in equal time as the planet orbits.

3. The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun.

… And Newton reduced it all to his Universal Law of Gravitation, and so it goes.

What is striking is role played by luck and also hyper-rationality - being too rational for your own good.

Why are there six planets, rather than five or seven?

This is a terrible question to approach purely rationally. First, it presupposes a falsehood; that there are only six planets. Second, the explanation for the number of planets in our or any solar system - even if you get the number right - turns out to be a matter of messy empirical details (of stamp collecting, if you will.)

Six is a number perfect in itself, and not because God created all things in six days; rather the inverse is true, that God created all things in six days because the number is perfect [1 + 2 + 3], and it would remain perfect, even if the work of the six days did not exist.

- St. Augustine

“When one is only interested in what went on in past centuries, one usually remains extremely ignorant of what is happening in this century”

- Rene Descartes, Discourse on the Method

“I am convinced that the most devoted of those who now follow Aristotle would think themselves happy if they had as much knowledge of nature as he had, even if it were a condition that they would never have more. They are like the ivy which does not seek to climb higher than the trees which support it, and which even often comes down again after reaching the top; for it seems to me that those people come down again, that is to say, become in some ways less learned than if they abstained from study who, not being content with knowing all that is intelligibly explained in their author, wish, in addition, to find in him the solution of many difficulties of which he says nothing and about which he perhaps never thought.”

- Descartes, Discourse on the Method

Russell on Leibniz’ philosophy: “an exposition of the system Leibniz should have written.” This is ambiguous between an examination of what he actually did (but imperfectly expressed) and an improvement of what he did, i.e. Leibniz version 2.0.

So the risk is splitting the difference in an unsatisfactory way - i.e. by doing semi-falsified history of European thought while at the same time doing unnecessarily-restricted philosophy of all the subjects one’s historical figures are discussing.

1 What is the nature of the human subject (the mind)? [Philosophy of Mind]

2 What is the nature of the world (matter)? [Metaphysics]

3 What is the nature of the relation between mind and matter, such that the former can know the latter? [Epistemology]

4 What is the nature of science? [Philosophy of Science]

To repeat:

Hence the logic behind the act of dividing the history of modern philosophy into a competition between two basic epistemological philosophies, i.e. two philosophies of the nature of knowledge.

To wit: rationalism and empiricism.

Rationalism seems to deny that thing Chalmers said …

The Intuition/Deduction Thesis: Some propositions in a particular subject area, S, are knowable by us by intuition alone; still others are knowable by being deduced from intuited propositions.

The Innate Knowledge Thesis: We have knowledge of some truths in a particular subject area, S, as part of our rational nature.

The Innate Concept Thesis: We have some of the concepts we employ in a particular subject area, S, as part of our rational nature.

Some (rough and ready) definitions:

“An empiricist will seek to relate the contents of our minds, our knowledge and beliefs, and their acquisition, to sense-based experience and observation. He will hold that experience is the touchstone of truth and meaning, and that we cannot know, or even sensibly speak of, things which go beyond our experience. A rationalist, on the other hand, holds that pure reason can be a source of knowledge and ideas; what we can meaningfully think about can transcend, and is not limited by, what we have been given in experience.”

- R. S. Woolhouse, The Empiricists

“Empiricists are like ants; they gather and put to use; but rationalists are like spiders; they spin threads out of themselves.” - F. Bacon

“One element in rationalist thought is a certain caution about the deliverances of the senses, and a belief that the correct use of reason will enable us to progress beyond the naïve, commonsense view of the world. Another is the vision of the universe as an ordered system, every aspect of which is in principle accessible to the human intellect. A further strand is a tendency to be impressed by mathematics both in virtue of its intrinsic clarity and certainty, and also because it is seen as a model for a well-founded and unified system of knowledge. And a final element. . . Is the belief in necessary connections in nature, and more, generally, the view that scientific and philosophical truth must involve reference to what, in some sense, cannot be otherwise.” - J. Cottingham, The Rationalists

1. Space is three dimensional.

2. All bachelors are unmarried.

3. If Sam is six feet tall, then he is at least five feet tall.

4. If the ball is red all over, then it is not also green all over.

5. Nothing comes from nothing (everything has a cause).

6. Nothing happens without a reason.

Putting it another way:

Mathematics most clearly (or most strikingly) exemplifies the character of a large class of thoughts - ‘pure’ thoughts, or products of ‘pure’ reason (perhaps); a priori knowledge; logical knowledge; conceptual truths:

For example:

The Pedestrian’s Problem

Entry Entry

Connector

Exit Exit

The Boatman’s Problem

Entry Exit

Connector

Entry Exit

This dispute is not really modern at all, but ancient and venerable indeed.

Just Plato versus Aristotle (courtesy of Raphael).

W. B. Coleridge:

“Every man is born an Aristotelian or a Platonist. They are the two classes of men, besides which it is next to impossible to conceive a third.”

Well, actually. . . Conceiving of the third class of men (and women: let’s be fair here) is really the task of figuring out what modern science is all about. Both mathematical and empirical.

A passage from Anthony Kenny’s, A Brief History of Western Philosophy, on Aristotle’s views of science and explanation.

“Science begins with observation. In the course of our lives we notice things through our senses, we remember them, we build up a body of experience. Our concepts are drawn from our experience, and in science observation has the primacy over theory. . .

“The great book of the Universe cannot be understood unless one can read the language in which it is written - the language of mathematics.” - Galileo

The Argument by Skeptical Hypothesis:

Let H by some extreme (Matrix-like) skeptical Hypothesis.

Let O be some rather Ordinary thing you think you know. (I have a hand in front of my face.)

Now the argument:

P1 I don't know that not-H.

P2 If I don't know that not-H, I don't know that O.

C I don't know that O.

From de Rose:

http://pantheon.yale.edu/%7Ekd47/responding.htm

Let me make this painfully obvious:

Let P be: ‘Miss Scarlet did it in the Lounge with the Knife.

In order to know the truth of P, we need to know the falsehood of Q, R and S.

Then Q will be: ‘Col. Mustard did it in the Library with the Lead Pipe.’

And R will we: ‘Mr. Green did it in the Ballroom with the candlestick.’

And S will be: ‘Prof. Plum did it in the study with the revolver.

In order to know whodunnit, where, and with what, you’ve got to eliminate all the alternative possibilities.

As any eight year old child will tell you: if you card looks like this, you don’t know whodunnit, where, and with what.