Knowledge is Power Bacon and Descartes

A Little History Of Science: Knowledge is Power Bacon and Descartes

In the century between Copernicus and Galileo, science had turned the world upside down. The earth was no longer at the centre of the universe, and new discoveries in anatomy, physiology, chemistry and physics reminded people that the Ancients did not know everything after all. There was a lot out there still to be discovered.

People also started thinking about science itself. What was the best way to do it? How could we be sure that new discoveries were accurate? And how could we use science to improve our comfort, health and happiness? Two individuals in particular thought deeply about science: one an English lawyer and politician, the other a French philosopher.

The Englishman was Francis Bacon (1561–1626). His father, Nicholas Bacon, rose from humble beginnings to become a powerful official for Queen Elizabeth I. Nicholas knew how important education is, so he sent his son to the University of Cambridge.

Francis, too, served Elizabeth, as well as King James I, after Elizabeth died. He was an expert on English law, took part in several important trials and, after he became Lord Chancellor, was one of the major legal figures of his time. He was also active as a member of parliament.

Bacon was very enthusiastic about science. He spent a lot of time doing chemistry experiments and observing all kinds of curious things in nature, from plants and animals to weather and magnetism. More important than any discovery he made were his elegant and persuasive arguments about why science was worth doing, and how it should be done. Bacon urged people to value science. ‘Knowledge is power,’ he famously said, and science is the best way to achieve that knowledge. So he encouraged Elizabeth and James to use public money to build laboratories and provide places for scientists to do their work. Scientists, he thought, should form societies, or academies, so they could meet and exchange their ideas and observations. Science, he said, offers humans the means to understand nature, and, by understanding, to be able to control her. Bacon wrote clearly about the best way for science to advance.

Scientists needed to make sure that the words they used were precise and easily understood by others. They needed to approach their investigations with open minds, instead of trying to prove what they thought they already knew. Above all, they must repeat their experiments and observations, so that they can be certain of their results. This is the method of induction. For example, by counting, weighing or mixing chemicals again and again, the chemist can become properly confident about what is going on. As scientists collect more and more observations, or inductions, they will become surer about what will happen. They can use these inductions to form generalisations, which in turn will show them the laws governing how nature works. Bacon’s ideas continued to inspire scientists for many generations. They still do so today.

So, in different ways, did those of the Frenchman René Descartes (1596–1650). He thought deeply about the work of both Harvey and Galileo. Like Galileo, Descartes was a Catholic who nevertheless passionately believed that religion should not come into the study of the natural world. Like Harvey, Descartes examined human and animal bodies and explained how they worked in ways that went far beyond what Galen had taught. In fact, even more than either Harvey or Galileo, Descartes tried to establish both science and philosophy on entirely new foundations. Although today we remember him mostly as a philosopher, he was much more of a practising scientist than Bacon.

Descartes was born in La Haye, in Touraine, France. A clever boy, he went to a famous school, La Flèche, in the Loire region, where excellent French wines are made. At La Flèche, he learned of Galileo’s discoveries with his telescope, Copernicus’s placing the sun at the centre of the universe, and the latest mathematics. He graduated in law at the University of Poitiers, and then he did a very surprising thing: he volunteered for an army of Protestants.

War raged in Europe during the whole of Descartes’ adult life (the Thirty Years War), and for almost nine years, he was part of it. Descartes never actually fought, although his knowledge of practical mathematics, and where cannon-balls might land, could have helped the soldiers. He was attached to both Protestant and Catholic armies during these years, and seemed always to be where important political or military events were taking place. We don’t know what he was doing, or how he got the money to travel so much. Perhaps he was a spy. If so, it was probably for the Catholics, to whom he always remained loyal.

Early in his adventures, on 10 November 1619, in a warm, stove- lit room, half asleep, half awake, he came to two conclusions. First, if he were ever to come to true knowledge, he had to do it all himself. The teachings of Aristotle and other authorities would not do. He needed to start over. Second, he concluded that the only way to start over was simply by doubting everything! Later that night, he had three dreams that he understood as encouraging this idea. He didn’t publish anything then, and in any case, his military adventures had just begun. But this decisive day (and night) started him on his path to explain the universe and everything in it, as well as the rules that might help others obtain scientific knowledge with confidence.

Doubting everything meant taking nothing for granted, and then, bit by bit, following your nose by accepting only things you can be sure about. But what could he be sure about? In the first instance, only one thing: that he was planning this scientific and philosophical project. He was thinking about how to arrive at certain knowledge, but, more simply, he was thinking. ‘Cogito, ergo sum,’ he wrote in Latin: ‘I think, therefore, I am.’ I exist because I am thinking these thoughts.

This simple statement was Descartes’ starting-point. That is all well and good, we might say, but what next? For Descartes, it had one immediate and far-reaching consequence: I exist because I am thinking, but I can imagine that I could think without having a body. However, if I had a body and couldn’t think, I wouldn’t know it. Therefore, my body and the thinking part (my mind, or soul) must be separate and distinct. This was the basis of dualism, the notion that the universe is made up of two completely different kinds of things: matter (for instance, human bodies, but also chairs, stones, planets, cats and dogs) and spirit (the human soul or mind). Descartes thus insisted that our minds – how we know we exist – have a very special place in the universe.

Now, people before and long after Descartes recognised that human beings are a special kind of animal. We have the ability to do things that no other animal has: to read and write, to make sense of the complexities of the world, to build jet planes and atomic bombs. Specialness was not the unusual part of Descartes’ separation of our minds and our bodies. The amazing step was what he did with the rest of the world, the material part.

Mind and matter are what the world is made up of, he said, and matter is the subject of science. This means that the material, non- thinking, parts of how we function can be understood in simple physical terms. And it means that all plants and all other animals, none of which have a soul, can also be completely reduced to matter doing its stuff. Along with trees and flowers, the fish and elephants are nothing but more or less complicated machines. According to Descartes, they are things that can be completely understood.

Descartes knew about automata, mechanical lifelike figures specially made to move and do certain things. We would call them robots. For example, a lot of seventeenth-century town clocks had little mechanical figures, often a man coming out on the hour to strike a gong. They were all the rage in Descartes’ day (and some still work now). People had already wondered if – since human beings could make such delicate figures, able to move and imitate humans or animals – perhaps a better mechanic could go one step further and make a dog that could eat and bark, as well as move.

Descartes had no desire to make these toys, but in his thinking, plants and animals were just extremely complicated automata, with no real feelings and only the capacity to respond to what was happening around them. These machines were matter, which could be understood by scientists in terms of mechanical and chemical principles. Descartes read William Harvey’s work on the ‘mechanical’ actions of the heart and the circulation of the blood, and he believed that this provided evidence for his system. (His own explanation of what goes on when the blood reaches the heart, and why it circulates, has been forgotten.) Descartes had great hopes that such ideas could explain much about health and disease, and ultimately offer human beings the knowledge of how to live, if not forever, at least for a very long time.

Having shown to his satisfaction that the universe is composed of two separate kinds of thing, matter and mind, Descartes puzzled how the human mind and its body were actually connected. He asked himself how they could be connected, if matter has substance and occupies space, and mind is the opposite, located nowhere and without any material basis at all. It had been common since the time of Hippocrates to associate our thinking powers with the brain. A blow to the head could knock a person out, and many medical men had observed that injuries and diseases of the brain led to changes in our mental functions. At one point, Descartes seemed to think that the human soul is located in a gland, in the middle of our brains, but he knew that, according to the logic of the system he had created, matter and mind could never physically interact. People later called this model of human beings ‘the ghost in the machine’, meaning that our machine-like bodies were somehow driven by a ghost-like mind, or soul.

The problem then was to explain how many dogs, chimpanzees, horses and other animals share so many of our mental capacities without having their own ‘ghosts’. Dogs and cats can show fear or anger, and dogs at least seem to be able to express love for their owners. (Cats are a law unto themselves.) Descartes’ curious mind puzzled over many other things: not surprising for someone who wrote a book called simply Le Monde (‘The World’). He accepted Copernicus’s ideas about the relation- ship between the earth and the sun, but was more careful than Galileo had been in presenting his ideas so that he did not offend the Church authorities. He also wrote about motion, falling objects, and other problems that attracted Galileo. Unfortunately, despite having some followers in his day, Descartes’ ideas about how the universe works could not compete with those of giants like Galileo and Isaac Newton, and few remember Descartes’ physics today.

If he lost out to clever men in the physics class, whether you know it or not, you follow in Descartes’ footsteps every time you solve problems in algebra and geometry. Descartes had the bright idea of using a, b, c in algebra problems to stand for the known, and x, y, z to stand for the unknown. So when you are asked to solve an equation such as x = a + b2, you are continuing the practice that Descartes started. And when you plot something on a graph, with a horizontal and a vertical axis, you are also using his invention. Descartes himself solved various algebraic and geometric problems in his book on those subjects, published along with the one on the world.

By so sharply separating body and mind, the material and the mental worlds, Descartes stressed how important the material world is for science. Astronomy, physics and chemistry deal with matter. So does biology, and if his idea of the animal-machine seems a bit far-fetched, biologists and doctors still try to understand how plants and animals function in terms of their material parts. It was just unfortunate for Descartes that his idea that medicine would quickly show people how to live for much longer was a bit before its time. He himself was pretty healthy until he accepted an invitation to go to Sweden to teach the Swedish queen his philosophy and knowledge of the world. She rose early and insisted that he give her the lessons very early in the morning. Descartes hated the cold. He did not survive even his first winter in Sweden.

Catching some kind of infection, he died in February 1650, seven weeks before his fifty-fourth birthday. It was a sad end for someone who believed that he would live at least a hundred years.

Bacon and Descartes had lofty ideals for science. They differed in their ideas about how science could advance, but were passionate that it should. Bacon’s vision was of science as a shared, state- funded enterprise. Descartes was more content to work things out by himself. Both wanted other people to take on and develop their ideas. Both men also believed that science is a special activity, superior to the humdrum of ordinary life. It deserved to be singled out in this way because science adds to our stock of knowledge and our ability to understand nature. Such understanding could improve our lives and the public good.