Well, let's go back to the very beginning. The birth of philosophy in ancient Greece.
Why did it happen? Well, who knows? It's very it's a very interesting and important fact about history.
That philosophy, as we understand it, seems only to have both been born once.
For some reason, the ancient Greeks, instead of relying purely on historical and religious myths,
started to ask about how they could understand the world rationally, not relying on tradition, but relying on reason.
They were, in fact, in ancient Greece, many different philosophers, many different schools.
Plato and Aristotle are obviously the most familiar today for a reason that we'll come to.
But there were lots of others, the pre Socratic philosophers, philosophers who preceded Socrates.
Socrates was the great teacher of Plato. Plato founded his academy from where the word academic comes.
The academy actually persisted for 800 years and there were quite a lot of different philosophers through that period.
Aristotle founded his own school, the Lyceum. Again, various philosophers came out of that.
There were various groups of sceptics, notably the Perrone and sceptics named after the philosopher Pyrrho Pierro.
If he said was so sceptical that he saw no reason for believing that falling off cliffs was dangerous.
No reason to believe that collisions with chariots were dangerous. So allegedly,
he had to be followed around everywhere by his friends who will pull it would pull him
out of the way whenever he got near a cliff or whenever a chariot came into view.
He's supposed to have lived to over 90. So I think his friends were quite successful.
Or maybe those stories aren't entirely true. The epicurean philosophers, the stoic philosophers, again, very famous schools of philosophy.
So there was a huge variety of philosophy in ancient Greece.
Now, unfortunately for philosophy, the Roman Empire became Christianised through Constantine originally, of course.
But later, Roman Empire emperors thought it was their moral and religious duty to actually close down the ancient schools of philosophy.
So, for example, a lot of libraries were destroyed and 391 A.D. in particular, the famous Library of Alexandria,
which contained huge numbers of ancient writings from these Greeks and not only for philosophical Greeks,
but also many great literary figures from the ancient world.
A huge number of their works were burned. We know about them only by report.
Sometimes fragments of these are discovered. Now ways are being found of actually recreating some texts, even from burnt fragments in 529 A.D.
All of the non Cristián Scutt schools were closed down. So Plato's Academy, which had been going for all those hundreds of years, was closed.
As a result, we have very few texts from these ancient philosophers, the ancient sceptic's, for example.
Their work is primarily known through only three texts.
One of them is Sextus Empirics outlines of Peronism. Another is Cicero's academical.
And the third is a work by a chap called Diogenes Laertes who wrote Lives of the Great
Philosophers with lots of little snippets describing their interesting lives and deaths.
For example, one of them allegedly jumped into a volcano to prove that he was a God.
I don't think the proof worked. Another one got dropsy.
And in order to cure himself, covered himself with dung and lay down in the marketplace.
And apparently the local dogs, not realising what it was, came along at 18.
So for many of these ancient philosophers, all we know about them is a few snippets in Diogenes Laertes.
And given that kind of story, you can see that we can't view them with tremendous authority.
Plato and Aristotle were somewhat privileged. Plato very early on played a part in the development of Christian doctrine.
If you look at Christian doctrine, such as the incarnation and the Trinity, there are clear signs of platonic thought.
Aristotle became a great authority in the later mediaeval period.
Most famously through Aquinas. You've seen the film. The name of the Rose.
Or read the book, for example. You see the sort of veneration with which Aristotle was held to in the later mediaeval period.
And this synthesis of Christianity and Aristotelian ism became totally dominant in the mediaeval monastic schools.
And so we get scholasticism. So scholasticism was the movement based on Aristotle, but developed beyond Aristotle,
incorporated into Christianity and tortas orthodoxy throughout Christendom.
Well, here is a sketch of Aristotle's universe.
You'll see that in the story that follows. Astronomy plays quite a significant role.
That might seem surprising, but I'm sure you'll understand soon.
The Aristotelian worldview view obviously places the earth right at the centre of the earth is surrounded by water or largely surrounded by water.
Beyond that, we have the sphere of air and fire, then the sphere of the moon, Mercury, Venus, the sun and so on.
The outermost crystalline sphere contains the fixed stars and these rotate around us, which is why we see the stars moving in the sky.
There's a sharp difference between everything below the sphere of the moon and things outside below in the subject.
Solutionary World. We have change, decay, the sorts of things that we are familiar with in the world beyond the moon.
Everything is perfect. Things move in perfect circles. They are unchanging.
That's the heavenly sphere. And we'll see that.
It was really the breaking apart of this picture that played a very major role in the development of modern philosophy.
Okay, so a number of things came about in the years between about fourteen hundred and fifteen hundred and a few decades thereafter,
which completely changed this intellectual landscape. Well, some ancient texts survived.
Now I've mentioned some of those that did like Sextus empirics outlines of Peronism
containing all these sceptical arguments that had been developed in ancient Greece.
Those were lost. But some of these manuscripts remained in the Byzantine world in Constantinople.
Some were translated by the Arabs and preserved in the Arabic world.
Well, eventually the Ottoman Turks attacked Constantinople.
It eventually fell. And at that point and prior to that, a lot of scholars fled to the west, bringing these precious manuscripts with them.
So a lot of these things were rediscovered. I find it extremely interesting that manuscripts that had been hidden away all that time had this dynamite
within them such that rediscovery of them could have such a profound effect on the Western world.
It really does show the value of what had been going on in ancient Greece,
that their philosophical discoveries, discoveries still have this power to unsettle the world.
So you have the development of humanism in Renaissance Italy, a new respect for classical thought.
People were trying to think through things in this new way, which was not totally dominated by the Cristián Aristotelian ism printing invented 14 50.
So these manuscripts suddenly got circulated very quickly amongst scholars in Western Europe.
So Lucretius direct the Reverend Archer and the nature of the universe rediscovered in 14 17 printed 14 86 Sextus empiric,
as I've mentioned, translated into Latin. Fifteen sixty two. Now lots of other things at this time happened to combine.
For example, population was growing. There was a lot of trade, a lot of trade with other countries.
There was the discovery of the new world. So 40 ninety-two, of course, Columbus sails the ocean blue to America.
This brought a lot of economic disruption.
They discovered a lot of silver down in South America, started bringing it back to Europe, cause all sorts of economic complications.
Course, they didn't realise what was causing this, but there was a lot of upheaval,
a lot of change as a result, the realisation that ancient maps were wrong.
Okay. For centuries, people had been going along thinking that Aristotle in the Bible between them contained more or less the whole truth.
And yet suddenly here we are discovering whole new parts of the world that aren't mentioned at all
by Aristotle or the Bible bound to cast some doubt on the ancient authorities cultural relativity.
You start meeting people who have other religious beliefs or other scientific beliefs.
They don't think the way we do. Well, that's bound to make you ask.
If you're at all reflective, how confident can we be that our views are right and there's a wrong technology,
gunpowder, centralisation of power again? Imagine what a difference it makes.
Once gunpowder has been discovered, it is no longer the case that somebody can simply sit walled up in their castle and wait for the enemy to go away.
Fundamental change in the technology of warfare inevitably brings big political differences,
and the very fact that Constantinople had fallen was partly due to this discovery.
So some of these things, you might think, well, how can they have an effect on the history of thought?
Well, the effect is to cause this massively complicated upheaval in all sorts of areas of life.
Suddenly, doubt is cast on all sorts of assumptions that people have taken for granted for generations.
A nice example of this, I think, is the Mappa Mundi. This is the famous map.
It's in Hereford, dates from about 12 '90, and it's based on the writings of Associates, who was a pupil of St. Augustine.
So this was based on a theory going back sort of 800 years.
And the view of the world had basically not changed over that time. That's the whole world.
Jerusalem is the centre of it.
Now, imagine that you have that kind of teaching that's come down for all those many hundreds of years, completely unchanged.
And then suddenly people start bringing back stories of far distant lands, America with lots of tangible evidence of a very different new world.
It's bound to have a profound effect on your worldview. And then, of course, along came the Reformation.
So in 15, 17, Luthor rebelled against the Church of Rome.
Quite a number of things. One of them was his objection to the selling of indulgences.
So if you were a churchman, you could get one of your parishioners who'd done something wrong.
You would persuade them that if they paid lots of money to the church, that it would go better for them in the afterlife.
And this was clearly an abuse. It was very widespread.
It's one of the things Luther protested against many parts of Europe, especially northern Europe.
Quickly became Protestant because Luther wasn't the only influence. People like Calvin and John Knox and so on.
But you ended up getting huge savage wars. The Thirty Years War, which meant was mainly fought over German lands, the civil war in England.
These were extremely vicious, nasty wars going on for a long time, setting family against family and so forth.
In 16, 48, you get a piece eventually, but it's described as a piece of exhaustion.
People are so fed up with all the religious war.
They don't want to go on killing each other. There isn't really a settlement in any theoretical sense.
It's not as though one side wins and the other loses. They just agree to differ.
So in the German lands, you get an agreement that essentially everybody has to obey the religion of their prints.
So if I live in a particular area and my prince happens to go Roman Catholic or Protestant, I have to follow.
And that clearly is just a compromise intended to stop the killing.
Now, imagine in the middle of all this, you read stuff written by these ancient sceptics,
in particular Sextus Empirics, and you naturally get to asking yourself this sort of sceptical question.
The problem of the criterion. Okay. I'm faced with two different people.
One person says the criterion of truth is religious tradition as taught by the church.
The other person says the criterion of truth is the word of God acting on you when you read the Bible.
Okay. How do I know which criterion is right? I've got the Roman Catholic criterion.
I've got the Protestant criterion.
What I'm looking for is some criterion for judging between them, but that is to ask for exactly the thing that I'm looking for.
How can any criterion of reliable knowledge be chosen unless we already have some reliable criterion for making that choice?
So this was a problem highlighted by the ancient sceptics and communicated to modern ages by Sextus Empirics had a big, very profound effect.