philosophy lecture 07

Introduction to PhilosophyIntroduction to Philosophy

IS-VNUIS-VNUMr. Mike Mr. Mike Lecture 7Lecture 7

Introduction to Philosophy

• The Enlightenment The Enlightenment • RationalismRationalism• Empiricism Empiricism

The EnlightenmentThe EnlightenmentBackground Background RenaissanceRenaissance Rediscovery of Ancient Greek Rediscovery of Ancient Greek PhilosophyPhilosophy

The EnlightenmentThe EnlightenmentBackground Background Protestant ReformationProtestant Reformation

Opposition to Church Opposition to Church Corruption and Abuse Corruption and Abuse of Powerof Power Rise of Religious Rise of Religious Violence Violence

The EnlightenmentThe EnlightenmentBackground Background Scientific RevolutionScientific Revolution

Copernican RevolutionCopernican Revolution Bacon's Scientific Bacon's Scientific MethodMethod Newton's Natural LawsNewton's Natural Laws Advances in technology Advances in technology and medicine and medicine

The EnlightenmentThe EnlightenmentEnlightenment ThemesEnlightenment Themes

ProgressProgress

Superiority of Reason Superiority of Reason

Superiority of Scientific Knowledge Superiority of Scientific Knowledge

Questioning Authority Questioning Authority

Opposition to Abuses Opposition to Abuses

Religious ToleranceReligious Tolerance

Freedom, Equality and Liberty Freedom, Equality and Liberty

Individualism - Individual Rights and FreedomIndividualism - Individual Rights and Freedom

Relativism Relativism

The EnlightenmentThe EnlightenmentRationalismRationalism

Appeal to Reason as the most accurate source of Appeal to Reason as the most accurate source of knowledge knowledge

Sensory Perception cannot be trusted Sensory Perception cannot be trusted

Truth is established through the intellect by Truth is established through the intellect by means of deductive reasoning means of deductive reasoning

Reason is established as the primary source of Reason is established as the primary source of knowledgeknowledge

Criticism Criticism

There is no rational reason why reason should be There is no rational reason why reason should be considered a valid form of knowledgeconsidered a valid form of knowledge

The EnlightenmentThe EnlightenmentRationalismRationalism

IntuitionIntuition is a valid form of rational insight. is a valid form of rational insight.

Intuition is knowledge that is immediate to us. It Intuition is knowledge that is immediate to us. It doesn't require reasoning or sensory experience. doesn't require reasoning or sensory experience.

A PrioriA Priori knowledge – Knowledge gained without knowledge – Knowledge gained without the use sensory experience. the use sensory experience.

Innate KnowledgeInnate Knowledge – Knowledge that we are born – Knowledge that we are born with. This knowledge is not learned by deductive with. This knowledge is not learned by deductive reasoning, sensory experience or intuition. It is reasoning, sensory experience or intuition. It is knowledge that is part of our nature as humans. knowledge that is part of our nature as humans.

The EnlightenmentThe Enlightenment

René DescartesRené Descartes (1596–1650)(1596–1650)

Rationalist Rationalist Believed that knowledge Believed that knowledge eternal truth could only be eternal truth could only be attained by reason aloneattained by reason alone Eternal Truths include: Eternal Truths include:

Mathematics Mathematics Philosophical foundations Philosophical foundations of scienceof science

Other areas of knowledge Other areas of knowledge such as physics require such as physics require sensory experience aided by sensory experience aided by the scientific methodthe scientific method



Set out to answer 2 questions: Set out to answer 2 questions: (1) What can I know? (1) What can I know? (2) How can I know it?(2) How can I know it? As a rationalist, Descartes set As a rationalist, Descartes set out to answer these questions out to answer these questions by means of reason alone. by means of reason alone.



Doubt (Skepticism) Doubt (Skepticism) Sensory experience can Sensory experience can sometimes be deceptive. sometimes be deceptive. Therefore, it must be doubted. Therefore, it must be doubted. Consciousness can also be an Consciousness can also be an illusion. When we dream we illusion. When we dream we believe that we are conscious.believe that we are conscious. Since sensory experience and Since sensory experience and consciousness are open to consciousness are open to error all beliefs about reality error all beliefs about reality should be doubted. should be doubted.



Method of Attaining Knowledge Method of Attaining Knowledge Establish truths which cannot Establish truths which cannot be gained through sensory be gained through sensory experience.experience. Establish truth which do not Establish truth which do not rely on consciousness of the rely on consciousness of the world outside yourself.world outside yourself. Establish truth though a Establish truth though a deductive process of deductive process of reasoning. reasoning.



Cogito Ergo Sum Cogito Ergo Sum I can doubt nature because it I can doubt nature because it relies on sensory experience. relies on sensory experience. I can doubt the existence of I can doubt the existence of other people because it relies other people because it relies on consciousness. on consciousness. Can I doubt my own Can I doubt my own existence? existence?

In order to doubt my own In order to doubt my own existence, I must first exist.existence, I must first exist.If I don't exist then I cannot If I don't exist then I cannot think about doubting. think about doubting. I doubt, therefore I think, I doubt, therefore I think, therefore I exist. therefore I exist.



Cogito Ergo SumCogito Ergo Sum ProblemProblem: : Only proves the Only proves the existence of your own mind but existence of your own mind but not your body or the external not your body or the external world. world.

If I exist, then it is possible If I exist, then it is possible that other things exist as well. that other things exist as well. Sensory experience is Sensory experience is something I do involuntary – I something I do involuntary – I experience things without experience things without trying to using my reason to trying to using my reason to sense things. Therefore, I sense things. Therefore, I must be sensing something. must be sensing something.



Cogito Ergo SumCogito Ergo Sum ProblemProblem: : Only proves the Only proves the existence of your own mind but existence of your own mind but not your body or the external not your body or the external world. world.

Perhaps an evil spirit is Perhaps an evil spirit is deceiving my sensory deceiving my sensory experience. experience. Descartes employs Anselm's Descartes employs Anselm's ontological argument to prove ontological argument to prove the existence of a good God the existence of a good God who does not deceive. who does not deceive.



Dualism Dualism Body – Body – Physical Physical

works like a machineworks like a machine has the material properties of has the material properties of extension and motionextension and motion it follows the laws of natureit follows the laws of nature



Dualism Dualism Mind – Non-physical Mind – Non-physical

nonmaterial entity nonmaterial entity lacks extension and motion, lacks extension and motion, does not follow the laws of does not follow the laws of nature nature only humans have mindsonly humans have minds the mind interacts with the the mind interacts with the body at the pineal glandbody at the pineal gland The pineal gland is the “seat The pineal gland is the “seat of the soul” of the soul”


Baruch Spinoza Baruch Spinoza (1632–1677)(1632–1677)

Jewish philosopher from AmsterdamJewish philosopher from Amsterdam

Spinoza called into question the Spinoza called into question the tenets of both Judaism and tenets of both Judaism and ChristianityChristianity

Believed in God but denied that the Believed in God but denied that the Bible was divinely inspired and Bible was divinely inspired and rejected the concept of miracles and rejected the concept of miracles and the religious supernaturalthe religious supernatural

Claimed that ethics determined by Claimed that ethics determined by rational thought were more rational thought were more important as a guide to conduct than important as a guide to conduct than was religionwas religion

The EnlightenmentThe EnlightenmentBaruch Spinoza Baruch Spinoza (1632–1677)(1632–1677)

Everything that exists in Nature is Everything that exists in Nature is one Reality (substance) one Reality (substance)

There is only one set of rules There is only one set of rules governing the whole of the reality governing the whole of the reality which surrounds us and of which which surrounds us and of which we are part. we are part.

God and Nature as two names for God and Nature as two names for the same realitythe same reality

God is the single substance that God is the single substance that is the basis of the universe and of is the basis of the universe and of which all lesser "entities" are which all lesser "entities" are actually modes or modifications.actually modes or modifications.

The EnlightenmentThe EnlightenmentBaruch Spinoza Baruch Spinoza (1632–1677)(1632–1677)

The mind and the body are The mind and the body are aspects of the same reality. aspects of the same reality.

There is no problem in Spinoza's There is no problem in Spinoza's metaphysics describing how the metaphysics describing how the mind and body are connected mind and body are connected since the mind and body are since the mind and body are essentially the same thing. essentially the same thing.

The EnlightenmentThe EnlightenmentGottfried Wilhelm von Leibniz Gottfried Wilhelm von Leibniz

Influential mathematician Influential mathematician

Invented calculus independent Invented calculus independent of Isaac Newton. of Isaac Newton.

Separated truth into 2 Separated truth into 2 categoriescategories

Synthetic Statements Synthetic Statements - - Truths which require Truths which require empirical verification empirical verification

Analytical StatementsAnalytical Statements - - Truths which do not require Truths which do not require empirical investigation empirical investigation


Synthetic StatementSynthetic Statement: :

My neighbor next door is a My neighbor next door is a very tall very tall manman with a very with a very short wife. short wife.

In order to prove this In order to prove this statement, I need to verify it statement, I need to verify it empirically empirically


Analytical StatementAnalytical Statement: :

My neighbor next door is a My neighbor next door is a very tall very tall bachelorbachelor with a very with a very short wife. short wife.

This statement can be proven This statement can be proven false without the need of false without the need of empirical verification empirical verification because it is a logical because it is a logical contradiction (i.e. bachelors contradiction (i.e. bachelors do not have wives)do not have wives)


Sufficient ReasonSufficient Reason: :

Analytical Statements – Analytical Statements – Can be proved true without Can be proved true without reference to external reality through logic or mathreference to external reality through logic or math

Synthetic StatementsSynthetic Statements – Must show the empirical cause – Must show the empirical cause of the statement. of the statement.

The EnlightenmentThe EnlightenmentGottfried Wilhelm von Leibniz Gottfried Wilhelm von Leibniz TheodicyTheodicy

Attempts to deal with the Attempts to deal with the problem of evil problem of evil

God could have created a God could have created a number of possible worlds number of possible worlds including a world without evilincluding a world without evil

The world God chose to create The world God chose to create (which includes evil) is the best (which includes evil) is the best possible world He could have possible world He could have createdcreated

Optimistic view of the world Optimistic view of the world

The EnlightenmentThe EnlightenmentEmpiricismEmpiricism

Knowledge comes only or primarily through Knowledge comes only or primarily through sensory experience sensory experience

Questions or even rejects the idea of a priori Questions or even rejects the idea of a priori knowledge or innate knowledge knowledge or innate knowledge

Criticism Criticism

Sensory perception can be deceived – dreamsSensory perception can be deceived – dreams

Sensory perception can be in error – Sensory perception can be in error – misjudgement misjudgement


John Locke John Locke Father of LiberalismFather of Liberalism British empiricistBritish empiricist All people were equal and All people were equal and

independent, and everyone independent, and everyone had a natural right to had a natural right to defend his “Life, health, defend his “Life, health, Liberty, or Possessions"Liberty, or Possessions"


John Locke John Locke The mind was a blank slate The mind was a blank slate

We are born without innate We are born without innate ideas ideas

Knowledge is instead Knowledge is instead determined ONLY by determined ONLY by experience derived from experience derived from sense perceptionsense perception

Complete rejection of a Complete rejection of a priori or innate knowledgepriori or innate knowledge


David Hume David Hume (1711–1776)(1711–1776) Skepticism Skepticism Suggested that our own Suggested that our own

senses are fallible, bringing all senses are fallible, bringing all observations and truths into observations and truths into question. question.

Very influential to others, such Very influential to others, such as Immanuel Kant, and was as Immanuel Kant, and was instrumental in the shift away instrumental in the shift away from rationalist thought that from rationalist thought that ended the Enlightenment.ended the Enlightenment.


David Hume David Hume (1711–1776)(1711–1776)

Problem of InductionProblem of Induction We believe that we can make We believe that we can make

inductive inferences from our inductive inferences from our observations observations

Induction relies on the belief that Induction relies on the belief that the pattern we notice when the pattern we notice when observing something are real observing something are real pattens pattens

There is no way to be certain that There is no way to be certain that an observed pattern will continue an observed pattern will continue to occur when unobserved to occur when unobserved


David Hume David Hume (1711–1776)(1711–1776)

Cause and EffectCause and Effect We observe a sequence of We observe a sequence of

events and attribute cause and events and attribute cause and effect to those events simply effect to those events simply because one followed the other. because one followed the other.

Yet there is no logical reason for Yet there is no logical reason for this assumption. this assumption.

If one event precedes another it If one event precedes another it does not necessarily make it the does not necessarily make it the cause. cause.

Billiards IllustrationBilliards Illustration


George Berkeley George Berkeley (1685-1753)(1685-1753)

ImmaterialismImmaterialism This theory denies the This theory denies the

existence of material existence of material substance and instead substance and instead contends that familiar objects contends that familiar objects like tables and chairs are only like tables and chairs are only ideas in the minds of ideas in the minds of perceivers, and as a result perceivers, and as a result cannot exist without being cannot exist without being perceivedperceived



ImmaterialismImmaterialism ““To be is to be perceived”To be is to be perceived” There is no existence There is no existence

without perception without perception Extreme empiricism Extreme empiricism



Problem of Immaterialism:Problem of Immaterialism: If a tree falls in a forest If a tree falls in a forest

with no one to perceive it with no one to perceive it does it make a sound? does it make a sound?

Does the forest even exist Does the forest even exist if no one perceives it? if no one perceives it?



Solution:Solution: God is also capable of God is also capable of

perception. perception. God is always perceiving God is always perceiving

the external world. the external world. Therefore, the world Therefore, the world

doesn't cease to exist doesn't cease to exist when we sleep because when we sleep because God continues to perceive God continues to perceive it. it.

philosophy lecture 07

Education

ren descartes

innate knowledge knowledge

use sensory experience

areas of knowledge

prioriknowledge knowledge

knowledge eternal truth

method of attaining

valid form of knowledge