Epistemology and Faith and Reason

MAYMESTER 2007

DAY 4

Rationalism

The main option to Empiricism is called Rationalism

We will consider the rationalism of Descartes.

Read: Rauhut on Rationalism

Read: Descartes Discourse on Method Part 4

<http://www.earlymoderntexts.com/pdfbits/dd34.pdf>

Rationalism vs. Empiricism

Rationalists think that they can know about REALITY by employing reason alone (i.e. there are parts of reality knowable by reason alone)…

Empiricists think that everything knowable is known through the senses, and the objects that motivate the rationalists are really products of the mind (Hume’s relations of ideas)

Rationalism (2)Historically Rationalism has been associated with

figures such as:

• Plato – (Theory of Forms/Recollection)

• Descartes – (Cogito/Clear and Distinct)

• Spinoza – (More Geometrico)

• Leibniz – (Truths of Reason)

Rationalism (3)

Making sense of Rationalism is difficult sometimes.

Rationalism usually emerges from either1) Thinking that knowledge has a special status

(indubitable, innate, necessary)

2) Thinking that there are special objects of knowledge (forms, necessary truths, numbers)

Different Rationalists emphasize these to different degrees

Rationalism Defined

Rationalism =

Our fundamental knowledge of the universe is provided by reason

Most Rationalists also admit that the senses can color our rational knowledge, but that the outlines are given by reason alone.

The main idea!

Rationalists (usually) do not reject sensory perceptions, but…

They hold that either:

1) Knowledge is fixed and unchanging –whereas the world of the sense is changing, or…

2) (At least some) Objects of knowledge are not given to the senses.

Unchanging Knowledge

Plato thought that knowledge required that the state of knowing be such that if you know P that cannot ever change.

The empirical world is limited and constantly changing

So, we cannot have empirical knowledge—only belief

Thus, if we have knowledge, it is not obtained empirically – Plato thus adopts innate ideas as the source of human knowledge

Special Objects of Knowledge

Plato’s Forms – Special Ideal Objects

Descartes/Leibniz:

Necessary Truths – Truths of Reason

How do we know them?:

Innate Ideas

Self-Evidence (C&D, Impossible to deny)

The Rationalism of Descartes

Descartes used the Principle of Hyperbolic Doubt to limit what counts as knowledge to those things which cannot be doubted.

His “foundation” for knowledge is:

Cogito ergo sum ; I think therefore I am.

Descartes: Cogito• The “Cogito” is the claim that I cannot

doubt that there is doubt.

• If there is doubt, then there is thought

• If there is thought, then there is a thinker.

• SO, if I doubt, then I think

• If I think, then I exist

• Thus, if I doubt, then I exist.

Descartes: Clear and Distinct Ideas

• According to Descartes, the distinguishing characteristic of the Cogito is that it is “CLEAR AND DISTINCT” (CD)

• So, Descartes reasons that if a belief B is CD, and God is not deceiving me, then I know B is true, so I know B.

• The truths of Logic, Mathematics, and Geometry are CD

• So are primitive sensory experiences (like Hume’s impressions)

Descartes: Rebuilding Knowledge

Descartes argues that if God exists, then we know that there is no Evil Demon deceiving us.

The first step in reconstructing knowledge is to prove that God exists. (We will get to that later)

Rebuilding knowledge

Once this is done, then Descartes can start to rebuild human knowledge by constructing an experienced world out of geometry and sense data.

Truths about this world, the world of science, can be known by reason alone.

Rationalist examples

The idea of God.

R: I have an idea of God, but I cannot get it through the senses.

E: You can make an idea of God using abstraction and imagination

R: OK, but why do we all make basically the same idea of God???

Rationalist examples (2)

The Pythagorean Theorem:

R: for all right triangles A2 + B2 = C2

E: I can discover this by trial and error, and others can confirm it.

R: OK, but I said “for all” not “for all up until now” There is a difference! I know that the theorem will hold in cases not yet tried, you don’t.

Rationalist JustificationA Rationalist might say:

A Belief in P is justified just in case P is a neccesary truth, or is deducible from a necessary truth.

Empiricists tend to be inductive reasoners

Rationalists tend to be deductive reasoners

Leibniz vs. Hume (Some similarities)

Leibniz (a rationalist/nativist) distinguishes between:

Truths of Fact (truths about the world)Truths of Reason (truths about ideas)

Hume (an empiricist) distinguishes between:Matters of Fact (what we know in experience)Relations of Ideas (what we know about ideas)

Four Kinds of Knowledge? (Kant)A Priori A Posteriori

Analytic(Relations of Idea)(Truths of Reason)

All Squares have 4 sides.

All fathers are male.2 + 2 = 4 (?)

NO NEED

Synthetic(Matters of Fact)(Truths of Fact)

2 + 2 = 4 (?) Tom is 6 ft tall.

It is 68 degrees outside.

Knowledge as Justified True BeliefIf Knowledge is Justified True Belief, then

a) Empiricist knowledge is true belief that is obtained through reliable sense experience.

b) Rationalist knowledge is true belief that is either necessary, deducible from a necessary truth, or innate.

A Summary of sorts… View K. is

PossibleK. Can be had by reason alone

K. is innate K. Comes from the senses

SkepticismNO _ _ _

Empiricism YES NO NO YES

Rationalism YES YES Some

times

Sometimes(must also

use reason)

Philosophy of Religion Slides2006

© Robert Barnard 2006

Philosophy and Religion

Historically Philosophy and Religion have been closely related.

Classical and Medieval Philosophers were often also religious thinkers or theologians

Augustine, Anslem, Aquinas, Plotinus, Duns Scotus, William Ockham, etc.

Some Issues in the Philosophical Approach to Religion:

1. Analysis of Religious Concepts

2. The role of Faith vs. Reason in ReligionIs Belief Rational?

3. How we can know God/Religious Truths(Religious Epistemology)

4. The existence of GodProofs for God

…by Faith alone?

• Tertullian – Credo Quia Absurdum“I believe because it is absurd”

• Kierkegaard – “The Leap of Faith”

But what do they believe?

And, how should we understand them?

Stances toward ‘God’

• THEISM – Affirms that God exists.

• ATHEISM – Denies that God exists.

• AGNOSTICISM – Neither affirms nor denies the existence of God. (Usually wants more evidence or a proof)

What do we mean by God?

We can use a single word to denote many ideas or objects.

Do we all mean the same thing by “God”?

What is God like?• IS GOD ETERNAL?• DOES GOD KNOW THE FUTURE?• IS GOD MALE OR FEMALE (OR SEXLESS)?• DOES GOD HAVE A PHYSICAL BODY?• IS GOD ALL POWERFUL (OMNIPOTENT)?• IS GOD ALL KNOWING (OMNISCIENT)?• IS GOD ALL-GOOD (OMNIBENEVOLENT)?• IS GOD THE GREATEST CONCIEVABLE

BEING?• ARE GOD AND JESUS THE SAME PERSON? • IS GOD EVERYWHERE (OMNIPRESENT)?

(After Rauhut, p. 172)

What is God like? (Part 2)

• DOES GOD HELP THOSE IN NEED?• DOES GOD CAUSE MIRACLES?• DOES GOD GET MAD AT HUMANS AND

PUNISH THEM?• DOES GOD LOVE ALL HUMAN EQUALLY?• IS GOD SO DIFFERENT FROM US THAT WE

HAVE NO CONCEPTION OF GOD?• IS GOD INFINITE?• DOES GOD HEAR YOU WHEN YOU SPEAK

TO GOD?• IS THERE ONE GOD OR MANY?

(After Rauhut, p. 172)

Varieties of Theism

• Classical Theism – Judaism, Christianity, Islam

• Pantheism – Shinto, Hinduism

• Pan-en-theism “everything is a divinity”

• New Age Theism

• Dualism – Zoroastrianism / Manicheanism

Classical TheismAccording to Classical Theism:

• God is a Person / Agent.

• God is capable of thought, desire, creativity, emotion.

• God acts in the world and can be in relations with humans.

The “Classical” PictureGOD IS (at least):

OmnipotentOmniscient

OmnibenevolentOmnipresent

RationalEternal

Arguments for Theism

• Arguments for the existence of God

If God exists, then denying God is embracing a falsehood

• Arguments for the rationality of belief in God.

Despite the fact that we cannot directly demonstrate the existence of God, there are still reasons to believe rather than remain agnostic.

Arguments for the existence of God

• Argument from Religious Experience

• Cosmological Argument

• Design Arguments

• Ontological Arguments

Argument from Religious Experience

1. I have experiences that seem to be caused by God.

2. Every effect has a cause.--------------------------------------

3. Therefore, God Exists.

Argument from Religious Experience (2)

Is the Inference Valid?

1. I have experiences that seem to be caused by the Easter Bunny

2. Every effect has a cause--------------------------------------------

3. Therefore, the Easter Bunny exists

Is this a counter-example? (too external?)

Argument from Religious Experience (3)

1. I have experiences that seem to be caused by a monster in my closet

2. Every effect has a cause.-------------------------------------------

3. Therefore there is a monster in my closet.

There are other possible causes of the experiences

Calling them Religious experiences is prejudicial

Cosmological Arguments

• In General, a COSMOLOGICAL argument argues from the fact that the world exists or has certain general features to the conclusion that GOD’s Existence is necessary to explain these facts.

• Aristotle and Aquinas are well known for making Cosmological Arguments of this kind.

Cosmological Arguments (2)

• The Key Assumption:

The Principle of Sufficient Reason:

For every event or object that exists there must be an explanation for that event or object.

Cosmological Arguments (3)

1. The Cosmos Exists (Observation)2. There must be a reason for the existence

of the Cosmos (PSR)3. It is possible that the cosmos didn’t exist,

so its cause must be necessary. 4. SO, if the cosmos exists a necessary

being exists. (1st conclusion)5. God is that necessary being (definition?)6. Therefore, God (necessarily) exists.

Cosmological Arguments (4)• This version of the CA depends upon

premise (3) that the cause of the universe is necessary.

To get (3) you must eliminate two possibilities

1. The cosmos is caused by a contingent physical event (e.g. Big Bang)

2. The cosmos itself exists necessarily (Brute Fact view)

Cosmological Arguments (5)

Possible Prima Facie replies:1. If the cosmos was caused by the big bang,

what caused the big bang? – causal regress is extended

2. If the existence of the universe is necessary by itself, why is that so? - Do we reject PSR? (Ad Hoc, we still apply it in other places)- Why does the necessary universe have these features and not others? (feeds the design argument)

Cosmological Arguments (6)

Worries about the CA

1. CA assumes PSR

2. CA assumes that the cosmos is contingent (not a brute fact)

3. CA assumes that God is the only possible necessary being (must a necessary being be God?)

4. Doesn’t rule out plural necessary beings

Conclusion: CA is not definitive

Next TimeThe Argument from Design

The Ontological Argument

The Rationality of Theism

-and-

The Problem of Evil

Read: Rauhut Chapter 7

Read: Descartes Meditations Meditation 3

(Reading: Http://www.earlymoderntexts.com/pdfbits/dm3.pdf )