0:00:11 > 0:00:16There is, in old Athens, a bookshop.
0:00:16 > 0:00:21It is the loveliest one I know. I discovered it 10 years ago
0:00:21 > 0:00:25and within it I found something wonderful.
0:00:27 > 0:00:30There, on a shelf, was a series of volumes,
0:00:30 > 0:00:33the collected, translated, works of Aristotle.
0:00:35 > 0:00:38Impressive, certainly.
0:00:38 > 0:00:41But I wasn't much interested.
0:00:41 > 0:00:45Philosophers and poets and playwrights may all worship
0:00:45 > 0:00:48at the shrine of Aristotle, but not scientists.
0:00:50 > 0:00:52And then I opened one.
0:00:55 > 0:00:58The book was called Historia Animalium,
0:00:58 > 0:01:01The Natural History of Animals.
0:01:01 > 0:01:06It told of snakes, sharks, and sea urchins, how they are built,
0:01:06 > 0:01:09where they live and what they do there.
0:01:09 > 0:01:13Assertion followed assertion, fact followed fact, like hammer blows.
0:01:13 > 0:01:18It was long, it was dense, it was impenetrable.
0:01:18 > 0:01:22And yet, it was magnificent.
0:01:23 > 0:01:28Aristotle, the man who gave us logic, poetics, political philosophy
0:01:28 > 0:01:35had also known, loved and sought to understand the natural world.
0:01:37 > 0:01:40Working by a lagoon on a Greek island, he investigated,
0:01:40 > 0:01:46analysed and documented the world of animals and plants.
0:01:46 > 0:01:49And did so in a wholly new way.
0:01:53 > 0:01:57There he discovered order in the chaos of organic diversity
0:01:58 > 0:02:00and there he invented a science.
0:02:04 > 0:02:09And though it was my science, biology, I did not know it.
0:02:09 > 0:02:12But then, hardly anyone does.
0:02:12 > 0:02:18For Aristotle's biology, strange, difficult and yet wondrous,
0:02:18 > 0:02:20is almost completely forgotten.
0:02:23 > 0:02:28In the 10 years since I found that book in an Athens bookshop,
0:02:28 > 0:02:30I've been living with Aristotle,
0:02:30 > 0:02:34trying to understand the workings of his astonishing mind.
0:02:34 > 0:02:36What did he do?
0:02:36 > 0:02:38Why did he do it? And how?
0:02:38 > 0:02:42And, most of all, why have we forgotten him,
0:02:42 > 0:02:46the first, and perhaps the greatest, biologist ever?
0:02:57 > 0:02:59The Scottish zoologist,
0:02:59 > 0:03:03D'Arcy Thompson, who translated Historia Animalium, wrote that
0:03:03 > 0:03:08the lagoon where Aristotle worked was on the Aegean island of Lesvos.
0:03:10 > 0:03:14That same day, I boarded the evening ferry from Piraeus.
0:03:19 > 0:03:24It's 347 BC and Aristotle is fed up.
0:03:24 > 0:03:27For 20 years he has been at Plato's Academy,
0:03:27 > 0:03:30first as a student, then as teacher.
0:03:30 > 0:03:34But now Plato is dead and there's vacancy at the top.
0:03:38 > 0:03:41Who should be the new head of the Academy?
0:03:41 > 0:03:45"Well", thinks Aristotle, "obviously it should be me."
0:03:45 > 0:03:47Intellectually voracious,
0:03:47 > 0:03:51in the philosophical hothouse, he's the best.
0:03:51 > 0:03:54Plato calls him The Reader.
0:03:54 > 0:03:58And he's original. Perhaps excessively so.
0:03:58 > 0:04:01In the event, the job goes to Plato's nephew.
0:04:01 > 0:04:04"Very well", thinks Aristotle.
0:04:04 > 0:04:07"I'll pack my bags and go where I'm appreciated."
0:04:10 > 0:04:12And off he goes.
0:04:12 > 0:04:15East, across the Aegean.
0:04:15 > 0:04:18GREEK STYLE MUSIC
0:04:23 > 0:04:26In the years that I have been searching for Aristotle,
0:04:26 > 0:04:29I have come to know and love this island.
0:04:34 > 0:04:37My dearest friend here is Giorgos Kokkoris,
0:04:37 > 0:04:41an ecologist at the University of the Aegean, Mytilini.
0:04:41 > 0:04:45It was he who first took me to the lagoon.
0:04:47 > 0:04:49And it is he who takes me there now.
0:04:54 > 0:04:58It was on the shores of this calm lagoon that, 23 centuries ago,
0:04:58 > 0:05:03Aristotle did so much of his ground-breaking biology.
0:05:05 > 0:05:06He knew it as Pyrrha.
0:05:06 > 0:05:08Today they call it Kalloni.
0:05:08 > 0:05:13But, for me, it is "Aristotle's Lagoon".
0:05:30 > 0:05:34Lesvos is the perfect place for a naturalist.
0:05:34 > 0:05:36In no other Greek island
0:05:36 > 0:05:42is the natural world so endlessly present and richly seductive.
0:05:42 > 0:05:45On the frontier of Europe and Asia,
0:05:45 > 0:05:48Lesvos draws its creatures from both.
0:05:48 > 0:05:52In spring and autumn, it is a resting place for millions of birds
0:05:52 > 0:05:56migrating between Africa and the north.
0:05:59 > 0:06:01What do we see over there?
0:06:01 > 0:06:03There are avocets.
0:06:03 > 0:06:09Filios Akriotis, Greece's leading ornithologist, lives on the island.
0:06:09 > 0:06:12He takes me for an Aristotelian walk
0:06:12 > 0:06:15in the marshes and woods that flank the lagoon.
0:06:22 > 0:06:26For me, science is an endless conversation about the world.
0:06:26 > 0:06:28Was it so for Aristotle?
0:06:28 > 0:06:30He came here to Lesvos
0:06:30 > 0:06:34at the invitation of a friend, Theophrastus.
0:06:34 > 0:06:37- At least, that's what many scholars believe.- Yeah.
0:06:37 > 0:06:41But who exactly was Theophrastus and what did he do?
0:06:41 > 0:06:42He was a botanist, I gather.
0:06:42 > 0:06:47Theophrastus was a botanist.
0:06:47 > 0:06:53He was another very special person of those times
0:06:53 > 0:06:57who has given us written descriptions
0:06:57 > 0:07:01of a very big variety of plants.
0:07:01 > 0:07:07Actually, many of the plants of today are named after Theophrastus,
0:07:07 > 0:07:10have their scientific names based on his name.
0:07:10 > 0:07:14Quite a remarkable person.
0:07:14 > 0:07:20One imagines the two men, friends, dividing up the natural world.
0:07:20 > 0:07:23"I'll do the animals", says Aristotle.
0:07:23 > 0:07:26"You, Theophrastus, do the plants".
0:07:26 > 0:07:30And so zoology and botany were born.
0:07:35 > 0:07:38Aristotle describes the forms, habits and habitats
0:07:38 > 0:07:40of hundreds of animals.
0:07:41 > 0:07:46He says that tortoises have shells, hiss, lay eggs and hibernate.
0:07:48 > 0:07:51That snakes copulate by entwining themselves.
0:07:53 > 0:07:56He describes the life cycle of the cicada.
0:07:58 > 0:08:04He tells of a bird with steel blue plumage, a long and slender beak,
0:08:04 > 0:08:08short legs that lives on rocks, obviously a rock nuthatch.
0:08:19 > 0:08:22He turns his attention to the water's edge.
0:08:22 > 0:08:24"In the shallows", he says,
0:08:24 > 0:08:28"the vegetation is more delicate and lush than any garden.
0:08:30 > 0:08:34"There is a kind of crab that has flattened hind limbs
0:08:34 > 0:08:36"with which it swims".
0:08:40 > 0:08:43He says that ibises, herons and egrets
0:08:43 > 0:08:46use their beaks as fishing spears.
0:08:50 > 0:08:55And that stilts are very quarrelsome and do not have a hind toe.
0:08:58 > 0:09:02And he describes the loveliest of the spring migrants,
0:09:02 > 0:09:04the European bee-eater.
0:09:04 > 0:09:09Aristotle notes their voracious appetite for bees, how they nest
0:09:09 > 0:09:14in holes that they dig in riverbanks and how they breed.
0:09:14 > 0:09:17And so, each year by the Lagoon,
0:09:17 > 0:09:20the bee-eaters still do.
0:09:20 > 0:09:25This is the philosopher discovering nature.
0:09:27 > 0:09:29He was not prejudiced by anything.
0:09:29 > 0:09:32He was not influenced by somebody who wrote about the same thing
0:09:32 > 0:09:36some time ago and had read about it when he was young.
0:09:36 > 0:09:41Yes, a freshness. That's what I admire in his writing.
0:09:41 > 0:09:44Everything he writes seems to be his own observations.
0:09:48 > 0:09:51In a wonderful passage known as the Invitation to Biology he says,
0:09:51 > 0:09:55"It's not good enough simply to study the stars,
0:09:55 > 0:09:58"no matter how perfect and divine they may be.
0:09:58 > 0:10:02"Rather we must also study the humblest creatures,
0:10:02 > 0:10:04"even if they seem repugnant to us.
0:10:04 > 0:10:09"And that is because all animals have something of the good,
0:10:09 > 0:10:12"something of the divine, something of the beautiful".
0:10:17 > 0:10:19But make no mistake,
0:10:19 > 0:10:22Aristotle is no mere naturalist.
0:10:22 > 0:10:27He collects facts, lots of facts, and arranges them.
0:10:27 > 0:10:31He's systematic, relentlessly so.
0:10:42 > 0:10:43He classifies.
0:10:43 > 0:10:46In Historia Animalium alone,
0:10:46 > 0:10:50he names and distinguishes 110 kinds of animals.
0:10:51 > 0:10:54And he's especially good on fish.
0:10:57 > 0:10:58Oh, nice.
0:10:58 > 0:11:00What is this beautiful thing?
0:11:00 > 0:11:02- Melanis.- Melanis. Melania.
0:11:02 > 0:11:04- Tsipouris.- Tsipouris.
0:11:04 > 0:11:10So, right here, we have about seven, eight, nine species of fish
0:11:10 > 0:11:14and they're all the fish that Aristotle describes.
0:11:14 > 0:11:16And he does so in wonderful detail.
0:11:16 > 0:11:20He talks about their forms and their proportions,
0:11:20 > 0:11:25where they live and how they breed and how they come into the lagoon,
0:11:25 > 0:11:26in and out every year.
0:11:32 > 0:11:37But Aristotle also notices that some species resemble each other.
0:11:43 > 0:11:50Aristotle classifies many of the creatures he finds in the lagoon
0:11:50 > 0:11:55into larger groups and you can see them here.
0:11:59 > 0:12:04Such as these things which I am trying to get.
0:12:04 > 0:12:07Which are sea squirts.
0:12:12 > 0:12:20He puts "sea squirts", so called because they squirt,
0:12:20 > 0:12:25and snails and sea urchins all in the same group, the ostracoderma,
0:12:25 > 0:12:29because they all have rather hard exteriors.
0:12:29 > 0:12:32He puts crabs, which also have hard exteriors,
0:12:32 > 0:12:36into a different group because they have legs.
0:12:36 > 0:12:41It's the beginning of the great classifications that we know today.
0:12:45 > 0:12:49Not all of his classifications have stood the test of time.
0:12:49 > 0:12:52Sea squirts, snails and sea-urchins are, in fact,
0:12:52 > 0:12:54quite unrelated to each other.
0:12:54 > 0:12:58But the 19th Century discovered that.
0:13:03 > 0:13:06And he's superb on dolphins.
0:13:07 > 0:13:11Aristotle notices that although dolphins live in water
0:13:11 > 0:13:16and look a bit like fish, they breathe air and suckle their young
0:13:16 > 0:13:18just as many land quadrupeds do.
0:13:18 > 0:13:22He therefore puts whales and dolphins, cetaceans,
0:13:22 > 0:13:23in a group of their own.
0:13:23 > 0:13:28His successors ignored him and just called them fish.
0:13:32 > 0:13:36What makes a scientist turn to the study of the natural world?
0:13:36 > 0:13:39So often, it is a place.
0:13:39 > 0:13:43And whatever that place is, it stays with him for the rest of his life,
0:13:43 > 0:13:47for it is where he first sees the beauty and delight of living things,
0:13:47 > 0:13:50begins to understand their mysterious order and glorious
0:13:50 > 0:13:57confusion and it is where he first begins to wonder why.
0:13:59 > 0:14:02And that is Aristotle's question.
0:14:02 > 0:14:06For he's in search of the deepest causes of things.
0:14:06 > 0:14:10And to do that, he knows that he can't simply go about
0:14:10 > 0:14:13pressing wild flowers and check listing birds.
0:14:13 > 0:14:17He has to get into the guts of things.
0:14:21 > 0:14:25But to do that, Aristotle first had to find a friendly fisherman.
0:14:25 > 0:14:27- Hey, Dimitri.- Hi, Armando.
0:14:27 > 0:14:29- Kalimera.- Kalimera.
0:14:29 > 0:14:33So what do you say? Let's do some fishing.
0:14:33 > 0:14:34Historia Animalium
0:14:34 > 0:14:38is so filled with observations about the creatures that live
0:14:38 > 0:14:43in and around the lagoon that they cannot all be Aristotle's own.
0:14:43 > 0:14:48He must have interrogated people who knew about animals.
0:14:48 > 0:14:53As Darwin wrote to pigeon fanciers, so Aristotle spoke to fishermen.
0:14:55 > 0:14:58So roughly where are we going? Are we going over there to the right?
0:14:58 > 0:15:01That direction. About in the middle. About in the middle.
0:15:01 > 0:15:03About half way down the lagoon.
0:15:03 > 0:15:10- Yeah.- The lagoon cuts the island of Lesvos nearly in two.
0:15:10 > 0:15:13It is one of the most productive stretches of water
0:15:13 > 0:15:14in the Eastern Aegean.
0:15:17 > 0:15:23And it contains an animal to which Aristotle was particularly devoted,
0:15:23 > 0:15:24the cuttlefish.
0:15:26 > 0:15:29The first few traps are empty.
0:15:29 > 0:15:31But there are cuttlefish down there.
0:15:31 > 0:15:33These are the eggs.
0:15:33 > 0:15:35Yeah.
0:15:35 > 0:15:37The net's just covered in them.
0:15:37 > 0:15:39- Exactly.- That's fantastic.
0:15:42 > 0:15:45God, there must be thousands and thousands of cuttlefish down there.
0:15:50 > 0:15:53You can see the embryo. Look.
0:15:53 > 0:15:55- Yeah.- You can see the embryo!
0:15:55 > 0:15:57I didn't expect that.
0:15:57 > 0:16:03I thought they stayed black all along, throughout their development.
0:16:03 > 0:16:05No, some of them, they haven't been sprayed.
0:16:05 > 0:16:09- Not all of them. Very few.- You mean they haven't been fertilised?
0:16:09 > 0:16:13Yeah. No, no, they have. But they are, usually when they are finished,
0:16:13 > 0:16:18- they spray with the ink to protect. - Oh, I see. I see.
0:16:18 > 0:16:21The ink is the last thing they do.
0:16:21 > 0:16:26But, the pale ones, you can see right inside them.
0:16:26 > 0:16:30And you can see the little baby cuttlefish.
0:16:30 > 0:16:33- Yeah, they're moving.- And they're moving, you're absolutely right.
0:16:33 > 0:16:37You can see its eyes. You can see exactly as Aristotle describes it.
0:16:44 > 0:16:47My god, they're gorgeous. They're amazing.
0:16:49 > 0:16:52In a week or two, they all will be gone.
0:16:54 > 0:16:57And then we see movement,
0:16:57 > 0:17:00cuttlefish, dozens of them.
0:17:07 > 0:17:10These weird, wonderful animals infest the lagoon
0:17:10 > 0:17:12and Aristotle has a lot to say about them.
0:17:12 > 0:17:15He describes how they change colour
0:17:15 > 0:17:19and how they eject ink when they're afraid.
0:17:19 > 0:17:23How they breed. How they hunt with these amazing long tentacles.
0:17:23 > 0:17:26And the fact that they only live for about a year.
0:17:40 > 0:17:46One of Aristotle's masterpieces is the dissection of the cuttlefish.
0:17:56 > 0:18:01Aristotle describes the anatomy of a cuttlefish in detail.
0:18:01 > 0:18:04He describes its gills over here,
0:18:04 > 0:18:07he describes its reproductive organs. This is a female.
0:18:07 > 0:18:11These are the glands with which it produces the shell.
0:18:11 > 0:18:16He knows that cuttlefish have a very unusual anatomy insofar that
0:18:16 > 0:18:22the guts are bent around such that, in effect, it defecates on its head.
0:18:22 > 0:18:27Its rectum is located very close to its brain and its eyes,
0:18:27 > 0:18:31underneath the mantle cavity, unlike most creatures whose rectums
0:18:31 > 0:18:34are at the opposite ends of their bodies from their mouths.
0:18:34 > 0:18:38The mouth, the beak,
0:18:38 > 0:18:43which is hard, with which it bites,
0:18:43 > 0:18:45over there.
0:18:45 > 0:18:49He looks inside of the cuttlefish and he sees that the biggest organ
0:18:49 > 0:18:54is a big orange thing, which he calls the mytis.
0:18:54 > 0:18:57And it's right in the middle of the body.
0:18:57 > 0:18:59He thinks that this is the heart
0:18:59 > 0:19:02or at least the equivalent of a cuttlefish heart.
0:19:02 > 0:19:06It isn't. It's the liver. But because it's centrally located
0:19:06 > 0:19:10and our hearts are centrally located, he, in effect,
0:19:10 > 0:19:12argues that they are the same thing.
0:19:12 > 0:19:15It's an easy mistake to make. And it must be said that
0:19:15 > 0:19:19everything else he does is just incredibly impressive.
0:19:25 > 0:19:29Aristotle's description of the anatomy of the cuttlefish
0:19:29 > 0:19:33was not bettered until the 17th Century when a Dutchman,
0:19:33 > 0:19:37Jan Swammerdam, found the cuttlefish's hearts,
0:19:37 > 0:19:40all three of them.
0:19:47 > 0:19:51You might expect that a book like this would be ordered by species,
0:19:51 > 0:19:55that there would be a chapter on insects and another chapter
0:19:55 > 0:19:58on the cuttlefish and lizards and so on and so forth.
0:19:58 > 0:20:01But it isn't. In fact, it's ordered by system.
0:20:01 > 0:20:07There are sections on digestion and reproduction and life cycles.
0:20:07 > 0:20:12Really, it's ordered like any modern invertebrate zoology textbook.
0:20:12 > 0:20:14And it's that that tells us that Aristotle
0:20:14 > 0:20:18isn't simply accumulating natural history knowledge.
0:20:18 > 0:20:20He's doing something much more systematic.
0:20:20 > 0:20:22He's doing science.
0:20:26 > 0:20:28And therein lies a paradox.
0:20:28 > 0:20:31The way in which Aristotle structured this book
0:20:31 > 0:20:35is so familiar to us, so very much a part of the way we think about
0:20:35 > 0:20:40the natural world and how we do biology, that it's almost impossible
0:20:40 > 0:20:44for us to understand just how original he was.
0:20:44 > 0:20:48And yet, when he came down to this lagoon,
0:20:48 > 0:20:53saw the creatures in it, cut them up and wrote down what he saw,
0:20:53 > 0:20:57he was the very first person to have ever done so.
0:21:02 > 0:21:07What he does next is revolutionary. Having sorted his data,
0:21:07 > 0:21:11having arranged his facts, he begins to explain.
0:21:11 > 0:21:14He pits theory against observation.
0:21:16 > 0:21:21He invents a new way of understanding the world.
0:21:27 > 0:21:30A COCK CROWS
0:21:32 > 0:21:37He applies this method to one of biology's deepest problems...
0:21:38 > 0:21:43..how life originates in the egg and in the womb.
0:21:43 > 0:21:49He wants to know how, the words are his, living things "come to be".
0:21:55 > 0:21:59If you really want to understand development,
0:21:59 > 0:22:01you have to do what Aristotle did.
0:22:01 > 0:22:02You have to go to a farmyard
0:22:02 > 0:22:05and get yourself some fertilised chicken eggs.
0:22:18 > 0:22:21One of the charms of this is that you just don't know
0:22:21 > 0:22:24what you are actually going to see until you open the egg.
0:22:26 > 0:22:28Sometimes, when you do,
0:22:28 > 0:22:32you see exactly what Aristotle saw.
0:22:33 > 0:22:37Aristotle would have looked inside the egg with the naked eye.
0:22:38 > 0:22:43But we can do a bit better with this handy microscope,
0:22:43 > 0:22:48which attaches to my computer. It's a little bit tricky,
0:22:48 > 0:22:51but if you focus it just right...
0:22:53 > 0:22:56..you can see what I'm seeing.
0:22:58 > 0:23:05It's an embryo, not more than a few days old, lying there, minute,
0:23:05 > 0:23:11on its bed of albumen and yolk. With the blood vessels,
0:23:11 > 0:23:16the vitelline arteries and veins ramifying into its surroundings.
0:23:16 > 0:23:18You can see its head.
0:23:20 > 0:23:21You can see its eye.
0:23:23 > 0:23:28And above all, you can see its little heart, just beating there.
0:23:30 > 0:23:33Even Aristotle's detractors, and he does have them,
0:23:33 > 0:23:35have to give him credit for this.
0:23:35 > 0:23:41He's the first person to open an egg and describe the embryo of a chick.
0:23:41 > 0:23:47He's the first person to describe the origin of a living thing.
0:24:00 > 0:24:04Aristotle describes the growth of an apparently inanimate egg
0:24:04 > 0:24:09into a living, breathing, copulating creature.
0:24:09 > 0:24:11Had he done just this,
0:24:11 > 0:24:14he would be worthy of our admiration.
0:24:14 > 0:24:16But I think he did much more.
0:24:16 > 0:24:21I think he attempted to, and largely succeeded in,
0:24:21 > 0:24:25penetrating to the very deepest secrets of life.
0:24:29 > 0:24:32Why do chicks hatch from chicken eggs?
0:24:32 > 0:24:35Why not tortoises, fish or snakes?
0:24:35 > 0:24:38It sounds like a trivial question, but it isn't.
0:24:38 > 0:24:42It's a question about why progeny look like their parents.
0:24:42 > 0:24:45It's a question about inheritance.
0:24:50 > 0:24:55Aristotle argued that the properties of matter, the elemental building
0:24:55 > 0:24:59blocks of the world, cannot explain how an embryo constructs itself.
0:24:59 > 0:25:02Something else is needed.
0:25:02 > 0:25:07Something that it gets from its parents, something that shapes it.
0:25:10 > 0:25:13And he called that thing eidos.
0:25:16 > 0:25:19Which is what, exactly?
0:25:19 > 0:25:23Well, this is where Aristotle gets hard.
0:25:23 > 0:25:27This is where he we hit his metaphysics.
0:25:29 > 0:25:32We need a classical philosopher.
0:25:32 > 0:25:34This is what one looks like.
0:25:34 > 0:25:40Richard King and I have been talking Aristotle for years.
0:25:40 > 0:25:42Aristotle takes a comparison between
0:25:42 > 0:25:48the material constituents of things, the elements, as he calls them,
0:25:48 > 0:25:51and the form or eidos. And he says,
0:25:51 > 0:25:57"The elements are like letters A and B and you can combine
0:25:57 > 0:25:59"them in various ways.
0:25:59 > 0:26:05"So you can either have the syllable AB or the syllable BA,
0:26:05 > 0:26:07"AB or BA, and the arrangement,
0:26:07 > 0:26:10"well, that's the form and the form is different in each case.
0:26:10 > 0:26:15"So the form is different from the material constituents".
0:26:16 > 0:26:20So what he seems to be saying is that it's not the stuff of which
0:26:20 > 0:26:24it's made that matters, it's the way in which that stuff is ordered.
0:26:24 > 0:26:29Exactly, exactly. It's the order of the material constituents
0:26:29 > 0:26:33just as the order of the letters makes the two different syllables.
0:26:33 > 0:26:37So what eidos really is is something like information?
0:26:37 > 0:26:42That's right. Information or a kind of activity.
0:26:42 > 0:26:45And the really remarkable thing is,
0:26:45 > 0:26:49he's using a metaphor for information,
0:26:49 > 0:26:53the order of the letters that is almost exactly like the metaphor
0:26:53 > 0:26:57that we use when we speak about the genetic code, about DNA.
0:26:57 > 0:27:01After all, it's not the material constituents of DNA that matter,
0:27:01 > 0:27:04rather it's the order of the elements of which DNA is made up,
0:27:04 > 0:27:08the molecules, the nucleotides, that's the information.
0:27:08 > 0:27:09That's right.
0:27:17 > 0:27:20One of Aristotle's methods for studying living things
0:27:20 > 0:27:26was simplicity itself. He cut them open while still alive.
0:27:32 > 0:27:37Aristotle has an enthusiasm for vivisection
0:27:37 > 0:27:40that today seems excessive.
0:27:40 > 0:27:45He describes how, if you cut an insect such as this in half,
0:27:45 > 0:27:47it lives for a surprisingly long time.
0:27:57 > 0:28:01Well, lots of modern biologists vivisect insects.
0:28:01 > 0:28:03But few vivisect chameleons.
0:28:03 > 0:28:06Aristotle did.
0:28:06 > 0:28:08"After being cut open", he observes,
0:28:08 > 0:28:13"the chameleon continues to breathe for a considerable time."
0:28:16 > 0:28:21And tortoises. "They", he says, "continue to wiggle their legs
0:28:21 > 0:28:23"even after their hearts have been removed."
0:28:25 > 0:28:30I don't know how long a tortoise would survive without its heart.
0:28:30 > 0:28:33And I am not, I think, inclined to find out.
0:28:33 > 0:28:37And yet Aristotle's belief that some creatures can survive
0:28:37 > 0:28:40for a surprisingly long time when eviscerated strikes
0:28:40 > 0:28:43to one of the deepest parts of his research programme.
0:28:43 > 0:28:48For when Aristotle cut out the heart of a tortoise,
0:28:48 > 0:28:53he was in search of nothing less
0:28:53 > 0:28:54than its soul.
0:29:06 > 0:29:11The ancient Greeks allegorised the soul as butterfly.
0:29:11 > 0:29:16They used the same name for both, psyche. It's easy to see why.
0:29:22 > 0:29:27The butterfly clambers from the dark chrysalis just as the soul,
0:29:27 > 0:29:30immaterial and immortal, flees a corpse at death,
0:29:30 > 0:29:35yet lives on in Hades. It's the soul as spirit.
0:29:40 > 0:29:43Aristotle's view of the soul is very different.
0:29:43 > 0:29:49He thinks that all living creatures, not just humans, have one.
0:29:49 > 0:29:54He thinks that mussels and clams and lobsters and crabs all have souls.
0:29:54 > 0:29:58Or at least they did when they were alive.
0:29:58 > 0:30:04For, Aristotle thinks, when a living thing dies, its soul dies with it.
0:30:09 > 0:30:13This is the soul as biology.
0:30:13 > 0:30:17Yet when you read Aristotle on the soul, it seems rather mysterious.
0:30:17 > 0:30:21It's not material, yet it controls matter.
0:30:21 > 0:30:25It's not an organ that you can dissect out and hold in your hand.
0:30:25 > 0:30:29It's something much more abstract.
0:30:30 > 0:30:35The soul is the network of command and control that makes a creature.
0:30:35 > 0:30:39It's the flow of nutrients throughout its body,
0:30:39 > 0:30:41it's the workings of its organs,
0:30:41 > 0:30:44it's the senses with which it perceives the world.
0:30:44 > 0:30:49And in the case of a man, it's the thoughts he thinks.
0:30:56 > 0:31:01It is what 21st century biologists simply call The System.
0:31:03 > 0:31:05It is a creature's metabolism
0:31:05 > 0:31:08and the circuitry of genes and proteins that control it.
0:31:11 > 0:31:17It is all the devices that stave off entropy and stop living things
0:31:17 > 0:31:20collapsing into heaps of inert matter.
0:31:23 > 0:31:27What Aristotle calls the soul, we call the system.
0:31:27 > 0:31:30What he calls eidos, we call genes.
0:31:30 > 0:31:34The language is very different but the concepts are much alike.
0:31:34 > 0:31:36At the heart of both theories of life
0:31:36 > 0:31:40is the idea that information handed down from parent to child,
0:31:40 > 0:31:45generation upon generation, shapes living matter.
0:31:49 > 0:31:54Aristotle believes that every species has a unique eidos,
0:31:54 > 0:31:56its own particular soul.
0:31:57 > 0:32:01Why, then, are there so many species?
0:32:01 > 0:32:04For us, there are two explanations,
0:32:04 > 0:32:10a religious one, God made them, and a scientific one, they evolved.
0:32:18 > 0:32:22Aristotle has a relentlessly scientific mind,
0:32:22 > 0:32:24but he lived 23 centuries before Darwin.
0:32:24 > 0:32:27So is he a creationist?
0:32:27 > 0:32:30His teacher Plato certainly was.
0:32:32 > 0:32:35Plato gives an account of the origin of animals,
0:32:35 > 0:32:40and it's a frank Creationist myth with a moralising twist.
0:32:40 > 0:32:42God made the cosmos and then,
0:32:42 > 0:32:45as punishment for various misdemeanours,
0:32:45 > 0:32:49turned some humans into animals. The frivolous became birds,
0:32:49 > 0:32:53the low-minded became lizards, snakes and things that crawl.
0:32:53 > 0:32:56Others became fish.
0:32:56 > 0:32:59Only the sober-minded remained human.
0:32:59 > 0:33:03Aristotle thinks all of this is nonsense.
0:33:03 > 0:33:07He has no time for creation myths, all that talk of the ancient Gods.
0:33:07 > 0:33:12"I love Plato", he said, "but I love truth even more".
0:33:15 > 0:33:19So is he an evolutionist?
0:33:19 > 0:33:22He has Darwin's sense of how creatures are fitted to
0:33:22 > 0:33:24the environments in which they live.
0:33:26 > 0:33:30He describes how the beaks of birds are suited to their food.
0:33:30 > 0:33:36"Creatures are", he says, "designed to survive and reproduce".
0:33:36 > 0:33:37And, he's quite clear,
0:33:37 > 0:33:41there isn't a celestial designer.
0:33:41 > 0:33:48Nature designs living things and does so beautifully.
0:33:56 > 0:34:02He thinks that some animals are more advanced than others.
0:34:02 > 0:34:05There is a scale of complexity.
0:34:08 > 0:34:12Most remarkably, he tells us that apes are intermediate in form
0:34:12 > 0:34:16between quadrupeds and humans, which is certainly true.
0:34:18 > 0:34:21It all sounds terribly Darwinian.
0:34:21 > 0:34:22But it isn't.
0:34:22 > 0:34:24For Aristotle isn't an evolutionist.
0:34:24 > 0:34:27He's something much stranger.
0:34:30 > 0:34:32Aristotle thinks that the world
0:34:32 > 0:34:37that we see before us has simply always been there, unchanging.
0:34:37 > 0:34:41He is, in other words, an eternalist.
0:34:43 > 0:34:46It's a difficult idea to understand.
0:34:46 > 0:34:50Our conceptual world is constructed on a Manichean conflict
0:34:50 > 0:34:55between Creation and Evolution and Eternity simply isn't an option.
0:34:55 > 0:34:59Eternity denies history.
0:34:59 > 0:35:04It says that the past is not a very different place,
0:35:04 > 0:35:10but the same place forever and forever and forever.
0:35:12 > 0:35:17Which brings us to one of the most puzzling gaps in his science,
0:35:17 > 0:35:21the fact that he doesn't say anything about fossils.
0:35:24 > 0:35:27It's hard to see how Aristotle missed this.
0:35:27 > 0:35:32We're on the western end of the island amid the remains
0:35:32 > 0:35:36of a vast forest, but the trees are now stone.
0:35:36 > 0:35:41It is one of the world's great petrified forests.
0:35:46 > 0:35:51Some people say that theory blinkers scientists.
0:35:51 > 0:35:56I don't think that's true, at least not in any strong sense.
0:35:56 > 0:35:58And yet,
0:35:58 > 0:36:01if you don't believe that the past is a different place,
0:36:01 > 0:36:05it's easy to see how you could mistake a forest
0:36:05 > 0:36:07for a field of stones.
0:36:09 > 0:36:12An ancient volcano covered them in ash.
0:36:12 > 0:36:13Now, 20 million years later,
0:36:13 > 0:36:17you can still see their leaves, bark and tissues.
0:36:20 > 0:36:23Aristotle's friend, Theophrastus,
0:36:23 > 0:36:28the founder of botany, lived just a few kilometres away in Erissos.
0:36:28 > 0:36:30Did he see them?
0:36:32 > 0:36:34I asked Nicholas Zouros,
0:36:34 > 0:36:38the Director of the Lesvos Petrified Forest, about it.
0:36:40 > 0:36:44We know that Theophrastus was born just next to Erissos
0:36:44 > 0:36:49and I am sure that once he visited this site.
0:36:49 > 0:36:52So, for me, it is quite obvious
0:36:52 > 0:36:57that he would have seen these silicified trees.
0:36:57 > 0:37:03For me, it's absolutely unbelievable that a person like Aristotle,
0:37:03 > 0:37:08or like Theophrastus, have not seen this.
0:37:12 > 0:37:15Perhaps he just missed the entire forest.
0:37:15 > 0:37:17Perhaps it was covered up.
0:37:17 > 0:37:22But I suspect that the real reason Aristotle doesn't mention this
0:37:22 > 0:37:25or any other fossil is not because he didn't see them,
0:37:25 > 0:37:28but because he didn't believe in them.
0:37:37 > 0:37:41Still, the question remains.
0:37:41 > 0:37:44If species weren't created and did not evolve,
0:37:44 > 0:37:48why then are there so many of them?
0:37:48 > 0:37:51Aristotle understands that species
0:37:51 > 0:37:54are connected to each other in very complex ways.
0:37:54 > 0:37:56He compares the world to a house,
0:37:56 > 0:38:00the Greek is oikos, from which we get our "ecology".
0:38:00 > 0:38:07And in the household of the world, every species has its own role.
0:38:12 > 0:38:17Aristotle knows that households are not always harmonious.
0:38:17 > 0:38:22He understands, as Darwin would, that there is a war of nature.
0:38:22 > 0:38:27But where in Darwinian wars some species flourish while others
0:38:27 > 0:38:34go extinct, in Aristotelian wars the combatants simply fight forever.
0:38:46 > 0:38:49But earthly creatures are not the only inhabitants of
0:38:49 > 0:38:54Aristotle's household, the sun, the planets and the stars are as well.
0:38:57 > 0:39:00His ecology embraces the cosmos.
0:39:00 > 0:39:06And regulating it all is God, a God who simply thinks.
0:39:06 > 0:39:11And though his God is the ultimate, remote intellectual,
0:39:11 > 0:39:15he is also the reason for life on earth.
0:39:18 > 0:39:23It's a beautiful, if slightly mystical, doctrine.
0:39:23 > 0:39:26For it says that the nature that Aristotle described,
0:39:26 > 0:39:30dissected and classified is, in fact, sacred.
0:39:34 > 0:39:36Had I a God...
0:39:36 > 0:39:38HAD I a God,
0:39:38 > 0:39:41he would surely be Aristotle's.
0:39:50 > 0:39:54Aristotle's world is very different from ours.
0:39:54 > 0:39:57Our world does have a history,
0:39:57 > 0:40:01one that can be seen in this very lagoon.
0:40:08 > 0:40:11Had Aristotle ever sat at this spot,
0:40:11 > 0:40:14he wouldn't have been by the water's edge.
0:40:14 > 0:40:16That's because tectonic movements
0:40:16 > 0:40:20have been shifting the islands beneath the Aegean.
0:40:20 > 0:40:24And for millions of years the shoreline has been rising.
0:40:29 > 0:40:33The ecology of the lagoon has changed, too.
0:40:33 > 0:40:39The most enchanting creatures that live here are surely the flamingos.
0:40:39 > 0:40:45For all their flamboyance, Aristotle does not mention them at all.
0:40:47 > 0:40:50They are newcomers and only arrived here a few decades ago.
0:40:55 > 0:40:59Other changes to the lagoon's ecology are more disturbing.
0:41:04 > 0:41:08Giorgos Kokkoris and his colleagues from the University of the Aegean
0:41:08 > 0:41:12have been monitoring the lagoon. They have found that pollution
0:41:12 > 0:41:15and over fishing are taking their toll on its creatures.
0:41:15 > 0:41:18I asked him about the lagoon's future.
0:41:20 > 0:41:22The problems that we have faced
0:41:22 > 0:41:27in this lagoon, these are the problems that we face
0:41:27 > 0:41:32in the entire Aegean. And actually, in the entire world, I would say.
0:41:32 > 0:41:37Biodiversity is threatened, fish catches have lowered.
0:41:37 > 0:41:41I think the situation will deteriorate and some day
0:41:41 > 0:41:44the fishermen will come and say that
0:41:44 > 0:41:48there is nothing else to fish down there.
0:41:48 > 0:41:50You know,
0:41:50 > 0:41:55I know that what's happening here is happening right across the Aegean
0:41:55 > 0:41:57- and the world.- It is.
0:41:59 > 0:42:04And as such, the lagoon is really just a microcosm
0:42:04 > 0:42:10of that larger picture of ecological devastation.
0:42:10 > 0:42:13And yet, for me,
0:42:13 > 0:42:17the fact that Aristotle worked here and that this
0:42:17 > 0:42:19is where biology began,
0:42:19 > 0:42:26makes the destruction of this lagoon a thing of unutterable sadness.
0:42:27 > 0:42:31If this lovely lagoon inspired Aristotle's vision
0:42:31 > 0:42:37of an eternal and harmonious world, then there is bitter irony
0:42:37 > 0:42:41in the fact that history has now caught up with it.
0:42:41 > 0:42:47GREEK STYLE MUSIC
0:42:55 > 0:42:58Aristotle continued the work that he began on Lesvos.
0:42:58 > 0:43:00He wrote books about the anatomy,
0:43:00 > 0:43:03physiology and development of animals.
0:43:03 > 0:43:05There is a book about breathing,
0:43:05 > 0:43:08another on ageing, another on movement.
0:43:08 > 0:43:11There is a book on the soul.
0:43:11 > 0:43:15The scientific legacy he left is not vast,
0:43:15 > 0:43:17it is monumental.
0:43:20 > 0:43:26It was read, copied and plagiarised by Roman encyclopaedists,
0:43:26 > 0:43:28Muslim physicians and Medieval scribes.
0:43:28 > 0:43:30By the 13th century
0:43:30 > 0:43:36it was being taught throughout the universities of Europe.
0:43:40 > 0:43:43In the Renaissance, scholars rearranged his books
0:43:43 > 0:43:47into catalogues with exquisite illustrations
0:43:47 > 0:43:51depicting the creatures that Aristotle had seen.
0:43:55 > 0:43:58They founded museums full of natural wonders,
0:43:58 > 0:44:01not unlike this one in a small village near the lagoon.
0:44:04 > 0:44:07In fact, it's no exaggeration to say
0:44:07 > 0:44:11that modern biology was founded on Aristotle.
0:44:15 > 0:44:18Which raises the question,
0:44:18 > 0:44:20why have we forgotten him?
0:44:20 > 0:44:27Why has he no place in the pantheon of great scientists next to, say,
0:44:27 > 0:44:29Pasteur or Darwin?
0:44:31 > 0:44:37One reason is that some of his biology was, very simply, wrong.
0:44:40 > 0:44:44He was very wrong about eels.
0:44:48 > 0:44:50Whoa! It's a big one.
0:44:54 > 0:44:57What a gorgeous fish.
0:45:02 > 0:45:04Which kind is it? Is it leptocephalous?
0:45:04 > 0:45:06- Leptocephalous.- Leptocephalous.
0:45:07 > 0:45:10Aristotle says that the eels grow from the mud
0:45:10 > 0:45:12at the bottom of the rivers.
0:45:12 > 0:45:18- Why would he say that? - Because basically he sees eels,
0:45:18 > 0:45:21even big ones, but especially small ones,
0:45:21 > 0:45:24they hide in the mud, they can easily just
0:45:24 > 0:45:29in the mud, just go... Go directly inside and disappear inside.
0:45:29 > 0:45:31In the mud.
0:45:31 > 0:45:35See, all this time, we never saw an eel with eggs.
0:45:35 > 0:45:38So what do you think that tells us?
0:45:40 > 0:45:43I don't know. This is a mystery.
0:45:43 > 0:45:46This is a eel mystery. Nobody knows.
0:45:46 > 0:45:52Well, marine biologists do know, but Aristotle certainly didn't.
0:45:54 > 0:45:57- See, he turns?- Yes.
0:45:57 > 0:46:00So when they bite they turn like that...
0:46:03 > 0:46:05I think we've got enough, don't you?
0:46:05 > 0:46:07Yeah.
0:46:13 > 0:46:19Aristotle noticed that eels are very unusual creatures.
0:46:21 > 0:46:25If you do a ventral incision,
0:46:25 > 0:46:28if you make a ventral incision of this sort,
0:46:28 > 0:46:31in order to look at its internal organs...
0:46:33 > 0:46:38..through to the rectum,
0:46:38 > 0:46:41down beyond,
0:46:43 > 0:46:46what you see are all the regular organs
0:46:46 > 0:46:49that you would find in any fish.
0:46:51 > 0:46:56But, in a regular fish,
0:46:56 > 0:47:01the reproductive organs would be somewhere right around here,
0:47:01 > 0:47:03the gonads, the sperm and the eggs.
0:47:03 > 0:47:07However, in eels, you simply never find them. Aristotle noticed this,
0:47:07 > 0:47:10and for him, it raised the obvious question,
0:47:10 > 0:47:16how, if an eel doesn't have eggs or sperm, does it reproduce?
0:47:18 > 0:47:22It's a reasonable question.
0:47:22 > 0:47:27He could, of course, not know that the European eel develops its gonads
0:47:27 > 0:47:30in the course of a 9,000 km swim
0:47:30 > 0:47:34to its spawning grounds in the Sargasso Sea.
0:47:39 > 0:47:44He seems to think that some kinds of creatures don't reproduce.
0:47:44 > 0:47:48They just appear from nowhere.
0:47:48 > 0:47:53- They "spontaneously generate", to use his term.- That's right.
0:47:53 > 0:47:58- What's all that about? - He noticed that some animals
0:47:58 > 0:48:03don't come about from animals of the same kind.
0:48:03 > 0:48:06So humans can produce tapeworms or fleas
0:48:06 > 0:48:12and he extends this to other animals, in other parts of nature,
0:48:12 > 0:48:16in the sea above all, but also with almost all insects.
0:48:19 > 0:48:22Quite why he does that is a very peculiar question.
0:48:23 > 0:48:27For nearly 2,000 years after Aristotle,
0:48:27 > 0:48:29as a consequence of Aristotle,
0:48:29 > 0:48:33people believed that lots of different creatures,
0:48:33 > 0:48:36insects, snails, clams, spontaneously generated,
0:48:36 > 0:48:38that they didn't actually ever reproduce.
0:48:38 > 0:48:40It had immense influence on biology.
0:48:40 > 0:48:43A disaster.
0:48:43 > 0:48:46One of Aristotle's less happy theories.
0:48:46 > 0:48:47Less happy theories?
0:48:47 > 0:48:50One of his catastrophic mistakes, I would say.
0:48:54 > 0:48:57Aristotle observed that putrefying flesh
0:48:57 > 0:49:01often seems to breed other creatures.
0:49:03 > 0:49:07Take this European glass lizard, which we have conveniently
0:49:07 > 0:49:12found dead at the side of a road.
0:49:14 > 0:49:18I'm cutting it up in order to see what's inside.
0:49:24 > 0:49:29The lizard has become rather mummified in the intense heat.
0:49:32 > 0:49:37We see, perhaps unsurprisingly,
0:49:37 > 0:49:42that it's crawling with maggots.
0:49:45 > 0:49:49Now, Aristotle knows that
0:49:49 > 0:49:52flies come from maggots
0:49:52 > 0:49:56and he knows that maggots come from
0:49:56 > 0:49:59putrefying flesh.
0:49:59 > 0:50:01And so he concludes,
0:50:01 > 0:50:04not unreasonably,
0:50:04 > 0:50:09that flies are, in his words, "spontaneously generated"
0:50:09 > 0:50:13from dead things.
0:50:16 > 0:50:20- You find these just here in Kalloni?- Just here in port.
0:50:20 > 0:50:22The fish from Kalloni, are they nice?
0:50:22 > 0:50:26- They are the very best.- The best. And I'll take one of these guys.
0:50:26 > 0:50:31Aristotle's belief in spontaneous generation wasn't, however,
0:50:31 > 0:50:33the real reason he became discredited.
0:50:33 > 0:50:38Rather, it was the failings in his method that this belief exposed.
0:50:38 > 0:50:40When I read Aristotle, it's like reading the work
0:50:40 > 0:50:44of a brilliant, albeit eccentric, colleague.
0:50:44 > 0:50:47There are the same detailed observations,
0:50:47 > 0:50:50the closely argued theory,
0:50:50 > 0:50:54the same invidious references to predecessors.
0:50:54 > 0:50:58But there's one thing that's missing,
0:50:58 > 0:51:04the thing that defines modern science...
0:51:07 > 0:51:09..experiment.
0:51:13 > 0:51:15I place two fresh fish in two jars,
0:51:15 > 0:51:20cover one with gauze and leave the other exposed.
0:51:20 > 0:51:23It's the kind of experiment that Aristotle might have done,
0:51:24 > 0:51:25but didn't.
0:51:25 > 0:51:29A week later, I look at the results.
0:51:30 > 0:51:33This fish has been left open
0:51:33 > 0:51:36and exposed to the elements.
0:51:40 > 0:51:43And it is
0:51:43 > 0:51:47crawling with maggots.
0:51:51 > 0:51:54Such as this one here.
0:52:04 > 0:52:07And the fish that has been covered in gauze, by contrast,
0:52:07 > 0:52:10there's plenty of rotting meat,
0:52:10 > 0:52:13but there aren't any maggots.
0:52:15 > 0:52:19And that proves that in order to get maggots in rotting meat
0:52:19 > 0:52:23you first have to get flies that lay eggs in them.
0:52:23 > 0:52:25And that, in all its simplicity,
0:52:25 > 0:52:30was the experiment that Francesco Redi did in 1668.
0:52:30 > 0:52:33It demolished Aristotle's theory of spontaneous generation.
0:52:33 > 0:52:37And his reputation never recovered.
0:52:58 > 0:53:01At the heart of this story lies a tragic paradox.
0:53:01 > 0:53:06For nearly 2,000 years, when men inquired about the natural world,
0:53:06 > 0:53:10they first asked, "What did Aristotle think?"
0:53:10 > 0:53:14And such was the force of his mind and the scope of his investigations
0:53:14 > 0:53:16that invariably he had an answer.
0:53:23 > 0:53:25And that was the problem.
0:53:25 > 0:53:30Aristotle, or rather his epigones, became an impediment to progress.
0:53:30 > 0:53:33The battle cry of modern science was sounded,
0:53:33 > 0:53:39"Study nature, not books" and by that, they meant Aristotle's books.
0:53:42 > 0:53:47He was turned into a symbol of the muddleheaded past
0:53:47 > 0:53:49and with some reason.
0:53:49 > 0:53:52He was the giant who had to be slain
0:53:52 > 0:53:56so that we could pass through the gates of philosophy
0:53:56 > 0:54:01and reach the green fields of scientific truths that lay beyond.
0:54:06 > 0:54:11Aristotle stayed in Lesvos for just two years.
0:54:11 > 0:54:17He was offered a job, tutor to a princeling called Alexander,
0:54:17 > 0:54:20whom history would call the Great.
0:54:20 > 0:54:23Later, he returned to Athens,
0:54:23 > 0:54:28where he founded his own philosophical school.
0:54:28 > 0:54:34He thought, wrote and, in 322 BC, died.
0:54:41 > 0:54:44What, then, are we to make of Aristotle?
0:54:44 > 0:54:47Should we praise him for his prescience,
0:54:47 > 0:54:50or condemn him for his errors?
0:54:52 > 0:54:56I think he gives us this. He tells us that creatures
0:54:56 > 0:54:59are exquisitely fitted to their environments.
0:54:59 > 0:55:05That they are adapted and that adaptation requires an explanation.
0:55:05 > 0:55:08He also says that complex things such as creatures cannot simply
0:55:08 > 0:55:11self assemble from their constituent parts,
0:55:11 > 0:55:14but rather that they need something else.
0:55:14 > 0:55:17They need information.
0:55:17 > 0:55:21And he tells us that if we want to understand living things,
0:55:21 > 0:55:25we have to take them apart, we have to reduce them down
0:55:25 > 0:55:29to their individual bits and pieces. But that once we have done so,
0:55:29 > 0:55:32we also have to put them back together again.
0:55:32 > 0:55:36For only when we do so will we really understand how they work.
0:55:36 > 0:55:40And it is this that, I think, makes Aristotle speak to us today.
0:55:40 > 0:55:45For if taking things apart was the task of 20th Century biology,
0:55:45 > 0:55:50putting them back together again is the task of the 21st.
0:55:53 > 0:55:58He is important because he gives us the very structure of our thought,
0:55:58 > 0:56:01even when we do not know it ourselves.
0:56:01 > 0:56:05His thought flows like a subterranean river
0:56:05 > 0:56:09through the history of our science, surfacing now and then as a spring,
0:56:09 > 0:56:14with ideas that are apparently new but are, in fact, very old.
0:56:22 > 0:56:27Is this view of Aristotle anachronistic?
0:56:27 > 0:56:29I don't think so.
0:56:29 > 0:56:35He is so vast, so protean, that each generation must read him anew.
0:56:35 > 0:56:36For when they do,
0:56:36 > 0:56:42they always find things in him that their predecessors have missed.
0:56:48 > 0:56:53Aristotle wrote thousands of sentences, but one,
0:56:53 > 0:56:57the first in his Metaphysics, defines him.
0:56:57 > 0:57:01"All men", he says, "desire to know.
0:57:01 > 0:57:07"But not all forms of knowledge are equal, the best is
0:57:07 > 0:57:11"the pure and disinterested search for the causes of things".
0:57:11 > 0:57:13And, he has no doubt,
0:57:13 > 0:57:17"Searching for them is the best way to spend a life".
0:57:17 > 0:57:24It's a claim for the beauty and worth of science.
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0:57:48 > 0:57:51E-mail subtitling@bbc.co.uk