After the Peloponnesian War

• Athenians lost confidence in their democratic government and began to question their values.

• At this time, several great thinkers appeared

– They were determined to seek the truth

– The Greeks called this great thinkers “Philosophers”

• Philosophers meant “lovers of wisdom”

• These Greek thinkers based their philosophies on the following two assumptions:

– The universe was put together in an orderly way, and could be changed

– People could understand the reasons for these changes through logic and reason

• One of the most famous philosophers was Socrates.• He encouraged the Greeks to question themselves and

their moral character.

“The unexamined life is not worth living”

• Socrates was admired by many, but his viewpoints puzzled many.

• In 399, when Socrates was 70 years old, he was brought to trial for “corrupting the youth of Athens” and “neglecting the city’s gods”.

• In his defense, Socrates says what he said was good.

– It encouraged the people of Athens to think about their actions and values.

• Unfortunately for Socrates, the court in Athens did not agree with this defense.– He was condemned to death in 399 B.C.

• Socrates’ student Plato, was about twenty years old when Socrates was executed.– Socrates was Plato’s teacher

• Plato wrote down the majority of his and his teacher’s conversations.

• Sometime in the 370’s B.C., Plato wrote his most famous book, The Republic.

• In The Republic, Plato documented his personal vision of a perfectly governed society.

• Not a democracy All citizens would fall into three groups:

– Farmers and artisans– Warriors– The Ruling Class

• In Plato’s Republic, the ideal ruler would be the person with the greatest insight from the ruling class.

– Would be chosen as philosopher-king

• Plato’s writings dominated Europe for the next 1,500 years.

• His main competition was his teacher and his own student Aristotle

• Aristotle questioned the nature of the world and human belief, thought, and knowledge.

• He invented a method for arguing using rules and logic Debate

• He applied his method of problem solving to psychology, physics, and biology.– His work provided the foundation of scientific

method used today

• His most famous student was Alexander of Macedonia Alexander the Great.

Hellenistic Culture

• As a result of Alexander’s conquering, a brand new culture emerged. – The Hellenistic culture

• A blend of Egyptian, Persian, and Indian influences– Language: A dialect of Greek

• Became an “educated” language and was spoken by people of many backgrounds.

• Among the many cities of this new Hellenistic civlization, the Egyptian city Alexandria became one of the most attractive cities in the world.

– Housed a great museum– Housed a massive library

• Became a center of intelligence

• The museum in Alexandria contained a small observatory in which astronomers could study space.

• Hellenistic astronomers made three great discoveries.

– The sun was three times larger than the earth– The earth was at the center of a galaxy.– The earth was between 28,000 – 29,000 miles wide

Corrections

• The sun is the center of the universe, not the earth.• The earth is about 24,860 miles.• Though these Hellenistic astronomers were incorrect, their

calculations were pretty impressive due to the lack of ancient technology.

Mathematics & Physics

• Hellenistic astronomers and mathematicians used a geometry text created by a Alexandrian teacher Euclid.

• Euclid wrote a book called Elements.– Contained 465 geometry propositions– Euclid’s work is still the basis for courses in

geometry

• Another important Hellenistic scientist, Archimedes of Syracuse, studied at Alexandria.

• He is credited for accurately estimating the value of pi– Pi is the ratio of the circumference of a circle to its

diameter• He also explained the law of the lever

• Archimedes invented several construction tools as well.– The Archimedes screw: a device that raised

water from the ground– The compound pulley

• Other Hellenistic scientists created other inventions and tools that we still use today.– The force pump and the steam engine