Chapter five: Democritus The last of the great natural philosophers, Democritus, agreed with his predecessors that transformations in nature could not be due to the fact that anything actually "changed." He therefore assumed that everything was built up of tiny invisible blocks, each of which was eternal and immutable. Democritus called these smallest units atoms. Democritus believed that natur...
The last of the great natural philosophers, Democritus, agreed with his predecessors that transformations in nature could not be due to the fact that anything actually "changed." He therefore assumed that everything was built up of tiny invisible blocks, each of which was eternal and immutable. Democritus called these smallest units atoms.
Democritus believed that nature consisted of an unlimited number and variety of atoms. Some were round and smooth, others were irregular and jagged. When a body--a tree or an animal, for instance--died and disintegrated, the atoms dispersed and could be used again in new bodies. Democritus did not believe in any "force" or "soul" that could intervene in natural processes. He is a materialist cause that he believed in nothing but material things.
The atom theory also explains our sense perception, thought Democritus. When we sense something, it is due to the movement of atoms in space. Democritus believed that the soul was made up of special round, smooth "soul atoms." When a human being died, the soul atoms flew in all directions, and could then become part of a new soul formation.This meant that human beings had no immortal soul.
Democritus's atom theory marked the end of Greek natural philosophy for the time being.
Chapter Six: Fate
Concurrently with the new directions in Greek philosophy, a Greek medical science arose which tried to find natural explanations for sickness and health. The founder of Greek medicine is said to have been Hippocrates, who was born on the island of Cos around 460 B.C.
The road to health for everyone is through moderation, harmony, and a "sound mind in a sound body."
Chapter Seven: Socrates（wisest is she who knows she does not know）
The natural philosophers are also called the pre-Socratics, because they lived before Socrates. Although Democritus died some years after Socrates, all his ideas belong to pre-Socratic natural philosophy. Socrates represents a new era, geographically as well as temporally.
In Athens, interest was now focused on the individual and the individual's place in society. Gradually a democracy evolved, with popular assemblies and courts of law.
The word "sophist" means a wise and informed person. In Athens, the Sophists made a living out of teaching the citizens for money. But at the same time the Sophists rejected what they regarded as fruitless philosophical speculation.
Socrates tried to show that some such norms are in fact absolute and universally valid. He spent most of his life in the city squares and marketplaces talking with the people he met there. "The trees in the countryside can teach me nothing," he said. The ability to give birth is a natural characteristic. In the same way, everybody can grasp philosophical truths if they just use their innate reason. At least he could have saved his life by agreeing to leave Athens. But had he done this he would not have been Socrates. He valued his conscience--and the truth-- higher than life. He was more concerned with man and his place in society than with the forces of nature.
Socrates called himself a philosopher in the true sense of the word. A "philosopher" really means "one who loves wisdom.""One thing only I know, and that is that I know nothing."
A philosopher is therefore someone who recognizes that there is a lot he does not understand, and is troubled by it.
Socrates, Athens and Plato
Socrates thought that no one cloud possibly be happy if they acted against their better judgement.
Socrates had pointed out that everyone could understand philosophical truths if they just used their common sense.
I mentioned that it could often be a good idea to ask what a particular philosopher's project was.
Briefly, we can establish that Plato was concerned with the relationship between what is eternal and immutable, on the one hand, and what "flows," on the other.
First you must think over how a baker can bake fifty absolutely identical cookies. Then you can ask yourself why all horses are the same. Next you must decide whether you think that man has an immortal soul. And finally you must say whether men and women are equally sensible.
Reason aspires to wisdom, Will aspires to courage, and Appetite must be curbed so that temperance can be exercised.
At school, a child must first learn to curb its appetites, then it must develop courage, and finally reason leads to wisdom.
Birds were chirping everywhere--in the trees and in the air, in bush and thicket.
Chapter one: at some point something must have come from nothing You can't experience being alive without realizing that you have to die, she thought. But it's just as impossible to realize you have to die without thinking how incredibly amazing it is to be alive. For the first time in her life she felt it wasn't right to live in the world without at least inquiring where it came from. Surely e...
Chapter one: at some point something must have come from nothing
You can't experience being alive without realizing that you have to die, she thought. But it's just as impossible to realize you have to die without thinking how incredibly amazing it is to be alive.
For the first time in her life she felt it wasn't right to live in the world without at least inquiring where it came from.
Surely everything that exists must have had a beginning? So space must sometime have been created out of something else. But if space had come from something else, then that something else must also have come from something. At some point, something must have come from nothing. But was that possible? Wasn't that just as impossible as the idea that the world had always existed?
Chapter two: The Top Hat
What is the most important thing in life? If we ask someone living on the edge of starvation, the answer is food. If we ask someone dying of cold, the answer is warmth. If we put the same question to someone who feels lonely and isolated, the answer will probably be the company of other people.
The best way of approaching philosophy is to ask a few philosophical questions:
How was the world created? Is there any will or meaning behind what happens? Is there a life after death? How can we answer these questions? And most important, how ought we to live? People have been asking these questions throughout the ages. We know of no culture which has not concerned itself with what man is and where the world came from.
My concern is that you do not grow up to be one of those people who take the world for granted.
Chapter three: The Myers
The myth tried to give people an explanation for something they could not understand.
She understood that people had always felt a need to explain the processes of nature. Perhaps they could not live without such explanations. And that they made up all those myths in the time before there was anything called science.
Chapter four: The Natural Philosophers
Natural philosophers were mainly concerned with the natural world and its processes, like
Is there a basic substance that everything else is made of?
Can water turn into wine? How can earth and water produce a live frog!
Greeks assumed that "something" had always existed. How everything could come from nothing was therefore not the all-important question.
The philosophers observed with their own eyes that nature was in a constant state of transformation. But how could such transformations occur? How could something change from being substance to being a living thing.
All the earliest philosophers shared the belief that there had to be a certain basic substance at the root of all change. They believe there must be a basic substance that was the hidden cause of all changes in nature. There had to be "something" that all things came from and returned to. They wanted to understand what was happening around them without having to turn to the ancient myths.
So philosophy gradually liberated itself from religion. We could say that the natural philosophers took the first step in the direction of scientific reasoning, thereby becoming the precursors of what was to become science.
The first philosopher we know of is Thales. Thales thought that the source of all things was water.
The next philosopher we hear of is Anaximander. He thought that our world was only one of a myriad of worlds that evolve and dissolve in something he called the boundless. It is not so easy to explain what he meant by the boundless, but it seems clear that he was not thinking of a known substance in the way that Thales had envisaged.
A third philosopher from Miletus was Anaximenes (c. 570--526 B.C.). He thought that the source of all things must be "air" or "vapor."
Parmenides thought that everything that exists had always existed. He thought that there was no such thing as actual change. Nothing could become anything other than it was. Parmenides realized, of course, that nature is in a constant state of flux. He believed that our senses give us an incorrect picture of the world, a picture that does not tally with our reason. As a philosopher, he saw it as his task to expose all forms of perceptual illusion.
This unshakable faith in human reason is called rationalism. A rationalist is someone who believes that human reason is the primary source of our knowledge of the world.
Heraditus said "Everything flows, cannot step twice into the same river". He pointed out that the world is characterized by opposites, "God is day and night, winter and summer, war and peace, hunger and satiety". He believed that there must be a kind of "universal reason" guiding everything that happens in nature. He said", The opinions of most people are like the playthings of infants."
Empedocles concluded the source of nature cannot possibly be one single "element". Empedocles believed that all in all, nature consisted of four elements: earth, air, fire, and wafer. Empedocles thought that it was "love" that joined the elements together in whole bodies.
Anaxagoras held that nature is built up of an infinite number of minute particles invisible to the eye. Anaxagoras also imagined "order" as a kind of force, creating animals and humans, flowers and trees. He called this force mind or intelligence (nous).