1. The Natural Philosophers
Brian Dunn
Honors Introduction to Philosophy
April 13, 2011

2. Who were the Natural Philosophers?
Also known as the Pre-Socratics because they preceded Socrates who died in 399 BC.
They all want to create general theories of the cosmos not through myth but through observation.
These philosophers are responsible for the birth of Western philosophy.
Beyond this, very little is known about them. Most of their writing disappeared long before Aristotle was born in 384 BC.
Most of their philosophies is only known today through the writings of Aristotle who summarized their beliefs.

3. Thales There must be a unifying, ultimately unchanging substance.
If there is change, there must be something that changes, yet does not change. There must be a unity behind all the changes in order for there to be a unified world.
There must be a unifying, ultimately unchanging substance.
He believed this substance was water.
All things are composed of water.
Value of Thales: not his conclusion, but his belief in an unchanging substance and for his introduction of reductionism.

5. Reductionism
A method of explanation that takes an object that confronts us on the surface as being one kind of thing and shows that the object can be reduced to a more basic kind of thing at a deeper but less obvious level of analysis.
This is the project of modern science, and Thales is considered the first to hypothesize this.

6. Things of this world can’t come from things of this world.
Anaximander
Questioned Thales’ assumption by asking, “How can water turn into fire?”
Things of this world can’t come from things of this world.
Everything in this world comes from the expansion or dissolution of another world. The force that mediates this is called the Boundless or the Unlimited, which is indefinable.

8. Anaximenes claimed that everything was “air.”
Criticism of Anaximander: “How much better is an indefinable something than nothing at all?”
Anaximenes claimed that everything was “air.”
What distinguishes objects from one another is how much “air” is packed into one object.

10. Thales, Anaximander, Anaximenes
These three are responsible for being the first to come up with two ideas that are now the foundation of modern science.
Naturalism- the view that natural phenomena must be explained in terms of other natural phenomena
Monism- the view that there is ultimately one kind of “stuff”

11. Heraclitus
Looked at fire and noticed its mix of stability (the flame’s form is stable) and change (in the flame, everything changes).
Looked at the changing quality of water as well.
Concluded that everything changes, but within this change is a logical force that’s orderly and not chaotic.

13. Parmenides
Everything that exists has always existed since nothing can come from nothing.
Nothing can become anything other than what it is.
Basically, he proposed that there is no such thing as change.
Though his senses told him that things change, his reason convinced him that they can’t. Parmenides choose to believe his reason.
Rationalism- belief in only reason for knowledge

15. Empedocles Rejected monism.
Believed all nature comes from four basic elements.
earth
air
fire
water
These four elements combine and separate only to combine all over again making new substances and changing old ones.
Think about a log burning.
The two forces that control everything, according to Empedocles, are love and strife.

16. Everything can be divided into smaller parts.
Anaxagoras
Believed that nature consists of an infinite number of invisible particles.
Everything can be divided into smaller parts.
There are fragments of everything in everything. Therefore, in your milk are tiny particles of blood and animals and people and trees, etc.
These tiny particles are called “seeds”
Similar to what in modern science?

18. Accomplishments of Pre-Socratics
Began the process of looking at the world through natural observation rather than myth.
Began to think about explanations that go beyond what’s observable to the naked eye.
Though none of their conclusions were correct, they asked the same sorts of questions that scientists would ask more than 2000 years later.
They did not blindly accept presuppositions spoken by people that claimed to have authority, which led to Socrates’ method of doing philosophy.

19. THANK YOU FOR YOUR ATTENTION!