Descartes. Meditations.

- He was in quest of valid (true) certain knowledge.(-Why?)

To establish the principal of practical conduct in a firm foundation (i.e. moral, political, educated principals)

- Is there at least one principal that is absolutely true?

Method. Systematic doubt.

Purpose: To discover a belief we can not doubt and use it as a model for establishing the truth of the preposition.

Well what the sources or means of knowledge?

Let us apply this method.

Skeptics and history.

Most will not support a philosophy.

Focus attention on establishing truth by a critical analysis of knowledge.

3 Cent BC. How does the skeptic cast doubt on a principal?

Human beings know in mind or body.

Skeptics chase the senses.



| - sweet 1. apple as it is in itself.

+ | - smooth 2. The apple as it appears to me.

| - crunchy

5 BC. PRORAGORAS - "Man is a measure of all things. " HOMO MENSURA

Man is a species - Man is an individual - knowledge.

Catholic or Jew - Skeptic.

God is the measure or source of knowledge

Stuff Matter.

Einstein - One person in the same motion as another appears to be stationary.

Preferences - What I like and don't like

Ex. X is good | beautiful

| true

Judgments are based on standards.

Values are included in judgments


|K| Standard

- X is beautiful





|T| Proof => Proof => Proof


Life is too short to prove to infinity.

Each philosopher gives a view.

A person reads and reads => What is the truth?

Will I change by adopting a new truth?

| Trial and error

| Validation.


Skeptic. Not truth but happiness.

Descartes. Founder of modern philosopher- Truth is foundation of human nature.

Newton- Set standards of science for 200 years..

Founded a system of knowledge on a foundation of principals and knowledge.

Principles of a practical life.

Institutions are based on true knowledge.

Education to

Education system => Justice.

[Knowledge} Where do I start? Answers to our prepositions to give truth.