Sophie’s World by Jostein Gaarder

Chapter:

The Natural Philosophers

The Philosophers’ Project

• Philosophers ask many

different questions.

• No one philosopher

concerns himself with

all of philosophy.

• Until the 20th century, it

was unusual for women

to be allowed to

philosophize publically.

The Natural Philosophers

• Were mainly concerned with the natural world and its processes.

• Observed that nature was in a constant state of change. How could such change occur?

• Believed there must be a basic substance at the root of all change.

• So their project was to determine what that basic substance was.

• We are interested in the questions they asked even if the answers they came up with were unsatisfactory.

• They posed questions relating to the transformations they could observe in the physical world.

• They wanted to understand what was happening around them without having to turn to the ancient myths.

• Philosophy separated itself from religion.

• These early natural philosophers were the precursors of today’s scientists.

graphic 1: http://www.kusadasi.tv/wp-content/uploads/Zeus-god-of-the-gods-greek-mythology.jpg graphic 2: http://www.lainesweb.com/page39/files/a-few-words-from-galileo.jpg

Three Philosophers from Miletus

Thales Anaximander Anaximenes

What is the basic substance of nature?

Miletus

Thales

• Lived about 624 BC –

546 BC

• Thought the source of

all things was water

Graphic: http://www.fcwa.org/story_of_water/images/animation/3forms.gif

Anaximander

• Lived about 610 BC–

546 BC

• Believed that our world

was one of many worlds

that evolve and dissolve

in something he called

the boundless

• (Greek: Apeiron)

http://conferences.inf.ed.ac.uk/hadoop11/images/hadoop.jpg

Anaximenes

• Lived 585 BC -- 528 BC)

• Claimed that the source of

all things was air.

– Water is compressed air

– Compressed water is earth

– Fire is rarefied air.

– So air is the origin of earth,

water and fire.

(rarefaction is the opposite of

compression)

Four Philosophers from Elea

Parmenides Heraclitus Empedocles Anaxagorus

How can one substance suddenly change into something else? – The Problem of Change

Elea

Parmenides

• Lived 5th century BC

• Everything that exists has always existed.

• Nothing can come out of nothing.

• Nothing that exists can become nothing.

• There is no such thing as change.

• Even though he observes change, reason tells him it is impossible.

• Rationalism: the belief that human reason is the primary source of our knowledge of the world.

Graphic: http://atlantarecoverycenter.com/wp-content/uploads/2011/06/bigstock_The_Brain_1701543.jpg

Heraclitus

• Lived around 535 – 475 BC

• Constant change is the most

basic characteristic of nature.

• The world is characterized by

opposites.

• God (Logos or Reason) is the

source of everything.

Graphic: http://farm1.staticflickr.com/60/164688726_b74b816cb2.jpg

Empiricism vs. Rationalism

• Parmenides

– Nothing can change

– Our sensory perceptions

must therefore be

unreliable.

• Heraclitus

– Everything changes

– Our sensory perceptions

are reliable.

Empedocles

• Lived around 490 – 430 BC

• Parmenides and Heraclitus and all the previous philosophers were wrong to look for one single element.

• Earth, air, fire and water do not change (Parmenides)

• Instead, they combine and recombine to form all that we see around us.

• Love is the force that binds the elements together; strife separates them.

Anaxagoras

• Lived around 500 – 428 BC

• Nature is made of an infinite number of minute particles smaller than the eye can see.

• Each of these “seeds” in a particular objects contains all of its parts

• Nous – meaning mind or intelligence is the force that creates order from the seeds.

Graphic: http://www.pericycle.com/wp-content/uploads/2008/09/nous21.jpg