THE ASCENT OF MAN

 JACOB BROWNOWSKI

MACDONALD FUTURA PUBLISHERS                        1973

PART III

 

Chapter 3: The Grain in the Stone

• The earth has existed for more than 4,000 million years, being shaped by hidden forces within the earth and erosion. Man has also become an architect of his environment but he does not command forces as powerful as those of nature.
• The Canyon de Chelly in Arizona is a breathless, secret valley, which has been inhabited by one Indian tribe after another without a break for almost 2,000 years.
• Why did civilization begin so much later in the New World than in the old? Evidently because man was a latecomer to the New World, crossing the Bering Straits when they formed a land bridge during the last Ice Age.
• The glaciological evidence points to two possible times when men might have wandered from the easternmost promontories of the Old World beyond Zsiberia to the Rocky wastes of western Alaska in the New.
• One period was between 28,000 BC and 23,000 BC, and the other between 14,000 BC and 10,000 BC. After that the flood of melt-water at the end of the last Ice Age raised the sea level again by several hundred feet and thereby turned the key on the inhabitants of the New World.
• That means that man came from Asia to America not later than 10,000 years ago and not earlier than 30,000 years ago. And he did not necessarily come all at once. There is subtle but persuasive biological evidence that I can only interpret to mean that he came in two small, successive migrations.
• The tribes of Central and South America (in the Amazon, in the Andes, and in Tierra del Fuego) belong entirely to blood group O; so do some North American tribes.
• Others (among them the Sioux, the Chippewa, and the Pueblo Indians) consist of blood group O mixed with 10% to 15% of blood group A.
• In summary, the evidence is that there is no blood group B anywhere in America. In Central and South America, all the original Indian population is of blood group O. In North America, it is of blood groups O and A.
• I can see no sensible way of interpreting that but to believe that a first migration of a small, related kinship group (all of blood group O) came into America, multiplied, and spread right down to the south.
• Then a second migration, again of small groups, this time containing either A alone or both A and O, followed them only as far as North America. The American Indians of the north certainly contain some of the later migration and are, comparatively speaking, latecomers.
• Agriculture in the Canyon de Chelly reflects this lateness. People are very simple, they have no houses, they live in caves. About 500 AD pottery is introduced.
• It seems the most natural thing in the world to take some clay and mould it into a ball, a little clay figure, a cup, a pit house. But there is another action of the human hand which is different and opposite. That is the splitting of wood or stone; for by that action the hand (armed with a tool) probes and explores beneath the surface, and thereby becomes an instrument of discovery.
• From an early time man made tools by working the stone. And from that simple beginning man prises open the nature of things and uncovers the laws that the structure dictates and reveals.
• The notion of discovering an underlying order in matter is man’s concept for exploring nature. The architecture of things reveals a structure below the surface, a hidden grain which, when it is laid bare, makes it possible to take natural formations apart and assemble them in new arrangements.
• For me this is the step in the ascent of man at which theoretical science begins. And it is as native to the way man conceives his own communities as it is to his conception of nature.
• The Canyon de Chelly is a microcosm of cultures, reaching its high point just after AD 1000, representing an understanding of nature in the stonework and of human relations.
• Stones make a wall, walls make a house, houses make streets, and streets make a city. A city is stones and a city is people; but it is not a heap of stones, and it is not just a jostle of people.
• In the step from the village to the city, a new community organization is built, based on the division of labour and on chains of command.
• A city must live on a base, a hinterland, of a rich agricultural surplus. At the heart of the terrace culture is a system of irrigation. This is what the pre-Inca empires and Inca empire made. Exactly as in the Fertile Crescent it is the control of water that matters.
• Exactly as in the Fertile Crescent it is the control of water that maters, so here in Peru the Inca civilization was built on the control of irrigation.
• A large system of irrigation extending over an empire requires a strong central authority, resting on an invisible system of communication by which authority was able to be present and audible everywhere, directing orders from the center and information towards it.
• Three inventions sustained the network of authority: the roads, the bridges, the messages. If they are cut then authority is cut off and breaks down – in modern times they are typically the first target in a revolution.
• It seems very strange that an architecture that moved large building stones on rollers could miss the use of the wheel; we forget that what is radical about the wheel is the fixed axle.
• It seems strange to make suspension bridges and miss the arch. And it seems strangest of all to have a civilization that kept careful records of numerical information yet did not put them in writing. The Inca was as illiterate as his poorest citizen, or as the Spanish gangster who overthrew him.
• It was an extraordinarily brittle empire. In less than a hundred years, from 1438 onwards, the Incas had conquered 3000 miles of coastline and yet in 1532 an almost illiterate Spanish adventurer, Francisco Pizarro, rode into Peru with no more than 62 terrible horses and 106 foot soldiers and overnight conquered the great empire by cutting the top off the pyramid – by capturing the Inca.
• A city is people. A city is alive. It is a community which lives on a base of agriculture, so much richer than in a village, that it can afford to sustain every kind of craftsman and make him a specialist for a lifetime.
• Paestum in Southern Italy was a Greek colony whose temples are older than the Parthenon: they date from about 500 BC. Paestum in ruins is one of the marvels of Greek architecture. Pythagoras taught in exile in another Greek colony at Crotone not far from here.
• Like the mathematics of Peru 2000 years later, the Greek temples were bounded by the straight edges and the set square. The Greeks did not invent the arch either, and therefore their temples are crowded avenues of pillars. The span that can be sustained by a flat beam is limited by the strength of the beam.
• The aqueduct at Segovia in Spain was built by the Romans about AD 100, in the reign of the emperor Trajan, spanning the valley for almost half a mile in more than a hundred double-tiered round arches made of rough hewn granite blocks, laid without lime or cement.
• Its colossal proportions so awed the Spanish and Moorish citizens in later and more superstitious ages that they named it El Puente del Diablo, the devil’s bridge.
• The structure seems to us also prodigious and splendid out of proportion to its function of carrying water. But that is because we get water by turning a tap, and we lightly forget the universal problems of city civilizations.
• Every advanced culture that concentrates its skilled men in cities depends on the kind of invention and organization that the Roman aqueduct at Segovia expresses.
• The Romans did not invent the arch in the first place in stone, but as a moulded construction made of a kind of concrete. Structurally the arch is simply a method of spanning space which does not load the center more than the rest; the stress flows outward fairly equally throughout.
• For this reason the arch can be made of parts: of separate blocks of stone which the load compresses. In this sense, the arch is the triumph of the intellectual method which takes nature apart and puts the pieces together in new and more powerful combinations.
• The Romans made the arch as a semicircle; they had a mathematical form that worked well, and they were not inclined to experiment.
• The circle remained the basis of the arch still when it went into mass-production in Arab countries. This is plain in the cloistered, religious architecture that the Moors used; for instance, in the great mosque at Cordoba, also in Spain, built in AD 785 after the Arab conquest.
• It is a more spacious structure than the Greek temples at Paestum, and yet it has visibly run into similar difficulties; that is, once again, it is filled with masonry, which cannot be got rid of without a new invention.
• The thrust of the Gothic arch makes it possible to hold the space in a new way, as at Rheims. The load is taken off the walls, which can therefore be pierced with glass, and the total effect is to hang the building like a cage from the arched roof.
• Of all the monuments to human effrontery, there is none to match these towers of tracery and glass that burst into the light of Northern Europe before the year 1200. The construction of these huge, defiant monsters is a stunning achievement of human foresight – or rather, I ought to say, since they were built before any mathematician knew how to compute the forces in them, of human insight.
• What must strike the mathematician most about the Gothic cathedrals is how sound the insight in them was, how smoothly and rationally it progressed from the experience of one structure to the next.
• In the 12^th century came the sudden revolutionary turning of that into the half arch: the flying buttress. The stress runs in the buttress as it runs in my arm when I raise my hand and push against the building as if to support it – there is no masonry where there is no stress.
• No basic principle of architecture was added to that realism until the invention of steel and reinforced concrete buildings.
• The arch, the buttress, the dome (which is a sort of arch in rotation) are not the last steps in bending the grain in nature to our own use. But what lies beyond must have a finer grain: we now have to look for the limits in the material itself.
• It is as if architecture shifts its focus at the same time as physics does, to the microscopic level of matter. In effect, the modern problem is no longer to design a structure from the materials, but to design the materials for a structure.
• The masons carried in their heads a stock, not so much of patterns as of ideas, that grew by experience as they went from one site to the next. Vertical and horizontal were related by the T-square, as they had been in Greek mathematics, using the right angle.
• The vertical was fixed with the plumb-line; and the horizontal was fixed, not with a spirit level, but with a plumb-line joined to a right angle.
• The fact of the matter is that our conception of science now, towards the end of the 20^th century, has changed radically. Now we see science as a description and explanation of the underlying structures of nature; and words like structure, pattern, plan, arrangement, architecture constantly occur in every description that we try to make.
• We talk about the way crystals are put together, the way atoms are made of their parts – above all we talk about the way that living molecules are made of their parts.
• The spiral structure of DNA has become the most vivid image of science in the last years. And the imagery lives in these arches.
• All imagination begins by analyzing nature. Michelangelo said that vividly, by implication, in his sculpture, and he also said it explicitly in his sonnets on the act of creation:

When that which is divine in us doth try

To shape a face, both brain and hand unite

To give, from a mere model frail and slight,

Life to the stone by Art’s free energy.

• ‘Brain and hand unite’: the material asserts itself through the hand, and thereby prefigures the shape of the work for the brain. The sculptor, as much as the mason, feels for the form within nature, and for him it is already laid down there. That principle is constant.

The best of artists hath no thought to show

Which the rough stone in its superfluous shell

Doth not include: to break the marble spell

Is all the hand that serves the brain can do.

• By the time Michelangelo carved the head of Brutus, other men quarried the marble for him. But Michelangelo had begun as one of the quarrymen in Carrara, and he still felt that the hammer in their hands and in his was groping in the stone for a shape that was already there.
• I have described the hand when it uses a tool as an instrument of discovery; it is the theme of this essay. We see this every time a child learns to couple hand and tool together – to lace its shoes, to thread a needle, to fly a kite or to play a penny whistle.
• This at bottom is responsible for every work of art, and science too: our poetic delight in what human beings do because they can do it.
• Even in prehistory man already made tools that have an edge finer than they need have. The finer edge in its turn gave the tool a finer use, a practical refinement and extension to processes for which the tool had not been designed.
• The most powerful drive in the ascent of man is his pleasure in his own skill. He loves to do what he does well and, having done it well, he loves to do it better.
• I could not end this essay without turning to my favorite monuments, built by a man who had no more scientific equipment than a Gothic mason. These are the Watts Towers in Los Angeles, built by an Italian called Simon Rodia.
• He suddenly decided to build, in his back garden, these tremendous structures out of chicken wire, bits of railway tie, steel rods, cement, sea shells, bits of broken glass, and tile of course – anything that he could find or that the neighbourhood children could bring him.
• It took him thirty-three years to build them. He never had anyone to help him because, he said, ‘most of the time I didn’t know what to do myself.’
• I am happy to say that the Watts Towers have survived, the work of Simon Rodia’s hands, a monument in the 20^th century to take us back to the simple, happy and fundamental skill from which all our knowledge of the laws of mechanics grows.
• The tool that extends the human hand is also an instrument of vision. It reveals the structure of things and makes it possible to put them together in new, imaginative combinations. But, of course, the visible is not the only structure in the world. There is a finer structure below it. And the next step in the ascent of man is to discover a tool to open up the invisible structure of matter.

 

Chapter 4: The Hidden Structure