Democritus and the Natural

PhilosophersGreek geeks and what they thought

This is a dead frog. Sometimes it’s a live frog. Except not when it’s dead. Which it is.

This is a block of ice. Sometimes it’s water. Except when it’s air—then it’s not water. Except

it is.

This is a baby. One day there wasn’t a baby, but then some stuff happened and then there was a

baby.

To some ancient Greeks, such natural details were peculiar and mysterious.

• Why do things die?• What is matter made of?• How can life come from

life?

These ancient Greeks were among the earliest Western philosophers and they focused on the

nature of matter and our senses.

They were primarily concerned with the physical world, which is where we get the name “natural philosophers.

However, they laid the groundwork for several other philosophical areas of study.

One of the most important distinctions that these natural philosophers made was a

separation between religion and philosophy.• The natural

philosophers wanted to know how nature worked. They were not satisfied with the explanations provided by mythology.

The natural philosophers used two primary tools to create their theories: Logic and

observation.

• A philosopher who relies primarily on logic to devise truth is known as a rationalist.

• A philosopher who relies primarily on observation and experimentation to devise truth is known as an empiricist.

The natural philosophers used these tools to describe how things changed

form, how nature worked, and how the universe may have begun.

One of the first natural philosophers was Thales.

• Thales believed that all things come from water. He observed that crops grew after it rained, and earthworms appeared as well.

• Thales also believed that “all things are full of Gods.” We don’t really know what he meant by that.

The next philosopher we hear about was named Anaximander.

• Anaximander believed that our world was only one of many that evolve and dissolve in something called the boundless.

• We don’t really know what he meant by ‘the boundless,’ but it’s clear that it is not a substance that is observable in the way that Thales believed. ‘The boundless’ contained some sort of divine property that water simply couldn’t explain.

• Thales was primarily an empiricist; Anaximander a rationalist.

A contemporary of these two philosophers was Anaximenes.

• Anaximenes heard Thales’ water theory, but wanted to know where water came from.

• He believed that water was pressed air, which he observed when water fell from the sky. Fire was also made of air, as was earth.

• Fire, earth, and water could therefore lead to life, but air was the source of everything.

These three philosophers all believed that one basic substance was the source of all

things. • But there was

still the problem of change. How does one thing change into another?

• One philosopher who tackled this was Parmenides. Parmenides did not believe that things actually changed.

• Instead, Parmenides believed that everything was stuck in a permanent state. Change was therefore an illusion created by our untrustworthy senses.

Parmenides used this chain of logic:

1. Something must exist. You can’t say “It is not” without saying “It”. Therefore, it is something.

2. “It” is rational; only what can be thought can exist. “Nothing” cannot be thought without thinking of something to contrast it. There is no nothing. There is thus only “being.”

3. “Being” is uncreated (“Something cannot come from nothing”), indestructible, eternal, and indivisible. Being has no holes because if Being “is”, there can’t be any place where Being is not.

Now, this view of reality may seem far fetched. After all, what is more obvious to

a person than the world of his senses?

But Parmenides’ student Zeno noticed certain problems with what our senses

told us about the world.

Specifically, the laws of math and logic collided with common experience in impossible ways. He’s described these occurrences

in a series of contradictions known as Zeno’s Paradoxes.

Zeno starts by describing an arrow shot from a bow. It appears to be moving towards its target.However, any object’s motion actually consists of a series of moments where the object is still.An object at any moment is still. Yet it appears to move. Paradox!

Another problem with our senses is

distance, which seems

fairly obvious.

Things are spread out!

However, if a man is going to go from

one place to another, he must first travel half

the distance.

… and before he can travel

that half distance, he must travel

half the half. And so on…

½ + ¼ + 1/8 + 1/16…

Zeno’s point was that an infinite

number of tasks must be

completed before anyone can go

anywhere. In fact, the trip can never

begin because there couldn’t

even be one first step!

Paradox!

Zeno’s most famous paradox is Achilles and the tortoise. In this situation, Achilles races a turtle,

but gives the turtle a 100 meter head start.

Both Achilles and the tortoise move at a constant rate. However, before Achilles can catch the tortoise,

he first reach the tortoise’s position…

…but unfortunately for Achilles, once he reaches the tortoise’s position, the tortoise has moved on. And once Achilles reaches that new

position, the tortoise has moved on again. Times infinity! Achilles can’t pass the tortoise!.

Paradox!

Opposing this illusory view of reality was Heraclitus.

• Heraclitus believed that change was the one constant in the universe. “Everything flows,” he said. “You cannot step into the same river twice.”

• He also believed that the universe was characterized by opposites– wet and dry, hungry and full, good and evil—and that all these states had their value in helping us perceive change.

• The one force that united these disparate elements was “God.” To Heraclitus, this was expressed as some sort of universal reason that is ultimately the source of everything.

• This “one force” that Heraclitus theorized is an example of the same sort of unifying laws that physics that Issac Newton advanced several centuries later.

Heraclitus’ theory of Logos influenced many.

• Plato was so taken with this concept that he based his theory of natural laws upon it.

• It is also directly related to a doctrine claimed by Christianity. Both God and Christ are equated with Logos in the Gospel of John: “In the beginning was the Word [Logos], and the Word [Logos] was with God and the Word [Logos] was God” (John 1:1); “And the Word [Logos] was made flesh, and dwelt among us.” (John 1:14) “The Word also gives

great backrubs!”

Parmenides and Heraclitus disagreed sharply.

• Parmenides thought that nothing changed and thus our sense lied to us.

• Heraclitus thought that change was constant and thus our senses were reliable. So who was right?

According to Empedocles, both. Neither.

• Parmendes was right in that nothing changes. A Rose cannot become a Revolver (except for Slash!).

• But Heraclitus was right to trust his senses. And our senses tell us that things change! Wood burns and becomes ash, water evaporates into air. But how?

• According to Empedocles, both Parmenides and Heraclitus had mistakenly assumed there was only one element. However, Empedocles believed there were four: Earth, Water, Wind, and Fire.

• Everything consists of these four elements– when we die, we are separating back into the constituent elements.

• Empedocles needed to explain how change therefore occurred. He described two forces—love and strife—that alternately bound things together or pulled them apart. This is the same sort of universal constant that we now ascribe to gravity, electromagnetism, and strong and weak nuclear force.

One philosopher who liked this idea was named Anaxagoras.

• Anaxagoras thought that nature was built of an infinite number of tiny seeds that we cannot see, and that everything can be divided into smaller parts.

• Furthermore, there are parts of everything in those fragments. For instance, if a frog has it’s leg cut off, there are plans for the entire frog in the leg of that frog!

• Be nice to frogs, guys.

According to Anaxagoras, the universe is not unlike a box of

Legos.

Anaxagoras believed the universe to be rational and intelligent

• There IS a force that pulls things together and apart. He called it “Nous”. Nous creates order from seeds.

• There is a distinction between animate and inanimate in that the living contain Nous within itself, while the inanimate world is ordered externally by Nous.

• Nous is qualitatively identical everywhere, but its abilities are determined by the nature of the body that contains it.

• Thus, humans aren’t any smarter than carrots, but they can do more than carrots because they have tongues, opposable thumbs, and legs. “Yeah, he’s cute,

but I hear he’s real dumb.”

Democritus of Abdera adopted Anaxagoras’ idea as his own.

• Democritus agreed that transformations can’t just happen and that the universe must consist of tiny invisible particles. He called these particles atoms.

• To Democritus, nature consists of unlimited variety of atoms that can be joined together to create different forms.

• When things died, Democritus believed that their atoms dissipate and could rejoin other forms because of their ‘hooks.’

• Democritus also believed that there were certain laws of nature that dictated how atoms (and thus all matter) could behave. These “causes of nature” meant that nothing happened randomly, but also that there was no conscious design of movement and transformation.

• Democritus also believed that men had souls also made of special “soul atoms” and that those atoms dissipated once you died. Thus, no one had an immortal soul.

Of course, some people have more soul atoms than others….

Democritus believed that all atomic Democritus believed that all atomic movement was governed by natural laws.movement was governed by natural laws.• To Democritus, there is nothing in

the world but material bodies in motion.

• There is no freedom, only necessity.• All behavior, all events, all

phenomenon are explainable based on analysis of the atomic beings and the natural laws that affect them.

• A thorough understanding of these would allow a being to perceive the future since all of nature is a deterministic mechanism. Seriously, guys… I don’t

want to talk about Donnie Darko.

Two and a half millennium later, where are we?

• Physics has observed the existence of atoms and a startling array of subatomic particles that help explain the “natural causes” that Democritus theorized.

• In July of 2012, scientists at the CERN Research Center announced the discovery of a particle they believe to be the Higgs-Boson, a long-theorized particle whose existence helps explain the presence of mass in the universe.

• These scientists often operate with the same mix of rationalism and empiricism that the natural philosophers employed.

• Their questions– what is dark matter, why is the universe full of matter rather than anti-matter—differ in substance (but not in purpose) from those original Natural Philosophers!

The L.H.C. supercollider began operating in late 2009. Let’s crash

some crazy %&*^) together!

The End!!