Science and socialists

Star wars

Paul McGarr (1988)

Published in Socialist Worker Review issue 112, September 1988, pp24-25.

Transcribed by Jørn Andersen for Marxisme Online, 3 december 2001.

One of the most popular courses at the recently held Marxism 88 was that on science. This month we begin a short series loosely based on that course. Here Paul McGarr writes on Copernicus, Kepler and Galileo.


In 1543 a little book by Nicolaus Copernicus was published in Germany. A century and a half later, in 1687, Isaac Newton in England published his work Principia.

The period marked by these dates has been rightly termed “the scientific revolution”. It saw the breakdown of the old view of the universe dominated by religious dogma and the birth of modern science.

There had been all sorts of theories and ideas about the universe in earlier times. For instance, in the third century BC, a Greek called Aristarchos had a theory in which the earth went round the sun. But given the level of observational technique and the nature of society at the time, it could not compete with the dominant theories which derived from the Greek philosopher Aristotle and later Ptolemy in Egypt.

Aristotle’s science was in part a simple reflection of everyday experience. He argued that objects did not move unless acted on by some force.

He also claimed the earth was the unmoving centre of the universe and that things had a natural place to which they tended to move. So, fire rises and stones fall. The approach is a crude reflection of everyday observation.

This picture only applied to the world below the orbit of the moon. Above that, in the realm of the planets, sun and stars, things were different. Here was the realm of divine harmony where the laws on earth did not apply. Everything was unchanging and perfect.

The problem was this theory didn’t fit observed facts. For example, if you look at the path of Mars in the sky it doesn’t move uniformly at all, even seeming to go into reverse at one point in the year. Such problems caused some to try and construct theories to “save the appearances”.

The culmination of such efforts came in the second century AD with Ptolemy in Egypt. He constructed a sophisticated mathematical model which did the job. The earth was at the centre and the planets and sun revolved around it on a complicated series of circles upon circles.

These theories were the orthodoxy in Europe in the time of Copernicus over a thousand years later.

By then the Roman Empire had disintegrated into localised feudal statelets, based on the forced extraction of surplus from the peasantry. Within these societies, especially after the turn of the millennium, there were two important developments – the growth of towns and of revolts from below, both of which represented potential challenges to the existing structure of society.

In such circumstances, ideological justification of the status quo was extremely important for the ruling class. The Catholic church, itself a key landowner and exploiter, was the vehicle for this. This is where astronomy came in.

Of course, peasants didn’t need to understand astronomy. But they did need to know that the universe and their place in it was constructed according to a divine plan which couldn’t be changed. To rebel would be pointless and indeed sinful.

The same applied to other challenges to the existing structure of society, such as from the new classes based on trade and commerce in the towns. And any ruling class needs an ideology which justifies its own position to itself. Thus, Aristotle’s theories, though banned by the church earlier, came to dovetail with what was needed.

Aristotle’s distinction between the laws on earth and those in the heavens implied you could not infer from experience on earth general truths about the universe. Enquiry and real knowledge was denied. A number of factors contributed to the breakdown of this orthodoxy, and to the breakdown of feudal society generally.

First was the destabilising influence of the towns. New forms of wealth and new classes grew, accommodating to existing society at first but nevertheless undermining aspects of it. There was also the growth of absolutist centralised states which attempted to restabilise feudal society while adapting it to a different and changing world.

New ways of thinking became possible because new social structures were evolving, the Renaissance and the Reformation being reflections of this. At a more fundamental level there were also big changes in the forces of production.

It is worth emphasising this because most academic discussion of the “scientific revolution” concentrates on ideas alone, omitting that those changing patterns of thought depended on changes in the way human beings interacted with and worked on nature.

In the period leading up to the scientific revolution, the padded collar and horseshoe transformed the horse into a useful beast. Increasing trade and commerce led to better navigation and time keeping techniques. The blast furnace and printing were developed in the 15th century, the first improving the tools that could be made, the second having a fantastically subversive effect on a rigid feudal society.

Also 1608 saw the first use of the telescope, significantly for military purposes.

It is in a society in which such changes are taking place, giving rise to tensions in the old social structures, that the “scientific revolution” is located.

In 1514 Nicolaus Copernicus was invited by the church to give his opinion on the question of calendar reform since the old Ptolemaic system no longer fitted. He tried to develop a simpler, more accurate system putting the sun at its centre.

When he gave lectures on his theory in Rome in 1533, the Pope approved of it as a calculating device.

In fact Copernicus’ system was neither more accurate nor simpler than Ptolemy’s, but it attracted support because it was a breach with the old orthodoxies.

Copernicus’s system meant that Aristotle’s explanation for falling bodies was no good and a new one would have to be found – the road to Newton’s theory of gravity was opened. Also, if the earth was no longer special then the whole notion of the laws on earth and in the heavens being different was shaken.

The demolition of the old way of looking at the world took another century to complete. This was the period of the Reformation, Counter-Reformation, the Thirty Years war and bourgeois revolutions in Holland and England. The key figures, in the scientific revolution of this period, were Tycho Brahe, Johannes Kepler and Galileo Galilei.

Johannes Kepler was Brahe’s assistant and successor, and the decisive figure in the “scientific revolution”. A dislocated individual in a crisis torn society, he spent several years living in poverty, and in central Europe as it was being ravaged by religious struggles and the Thirty Years war.

His early ideas were characterised by wild speculative theories, one explained the layout of the planets in terms of musical notes. But later he made a number of important breakthroughs towards a scientific approach.

Firstly, he was prepared to ditch theories if they didn’t fit the facts. Secondly, he saw theories as explanations for the way things really were, not just as calculating devices. And third and most importantly, he looked for explanations of planetary motion in terms of the experience of moving bodies on earth.

This is the decisive step in the scientific revolution. Real knowledge becomes possible on the basis of generalising and abstracting from our immediate experience.

Kepler drew on work by a man called Gilbert, on magnetism (itself connected with the need for better navigation to help trade and commerce), and tried to explain planetary motion as clue to magnetic force. He was wrong but drat is secondary. It is the method that is crucial. The attempt to generalise from experience involved in Kepler’s approach lays the basis for Newton and his famous apple.

The final steps in the breakdown of the old dogmas were the work of Galileo Galilei.

He systematically used experiments to try and learn about the world. After learning of the telescope in 1609 he built one and turned it to the sky. What he saw was the final nail in the coffin of the old world view.

The heavens were far from perfect and unchanging. The surface of the moon was irregular, Jupiter had satellites, comets wandered irregularly through the solar system. And worst of all, the sun had spots!

However the acceptance and development of Kepler and Galileo’s new ideas depended on two factors.

The first was whether they worked, whether the new theories of astronomy helped navigation, allowed better time keeping and so on. This is the ultimate test of any ideas which claim to be scientific. But their acceptance also depended on the outcome of struggles over the structure of society, that is the outcome of class struggles. This is illustrated by what happened to Kepler and Galileo.

The very crisis which allowed new ideas to be developed also produced a reaction among those concerned to defend the staus quo. Copernicus had been well received by the Pope in 1533. A year later the Jesuits and the Roman Inquisition were formed as the shock troops of the Counter-Reformation.

This reaction to the religious dissent unleashed by Martin Luther in 1517 had been slow in developing, but when it arrived it was vicious.

Religious conflicts, a reflection of the clash between the old feudal order and a new bourgeois society, turned Europe upside down. There were bloody civil wars like that in France in the late 16th century, and then from 1618 to 1648 the Thirty Years war which ravaged central Europe.

Kepler and Galileo were a product of this crisis but also the victims of reaction trying to reimpose order and orthodoxy. Kepler’s work was banned by the Catholic church in the 1620s and the Jesuits denounced Galileo’s work as “more dangerous than the teaching of Luther and Calvin put together”, which is a bit like Reagan saying someone is worse than the Ayatollah and Colonel Qadhafi combined!

Galileo was particularly dangerous because he wrote in ordinary Italian, rather than the elitist Latin. He was convicted of heresy, forced to recant, and spent the last years of his life under house arrest. But though reaction tried to roll back new ideas in much of Europe it did not succeed everywhere.

The invention of printing meant that ideas now had a far wider circulation than ever before. In the years that followed, in the mid 17th century, the scientific revolution was taken up and completed in two places in particular.

Firstly in Holland, where the “free” printing presses of the bourgeoisie were crucial in keeping ideas alive and secondly in England by people such as Isaac Newton. In other words in those countries where the crisis of the old order had not resulted in the victory of reaction.

Where bourgeois revolutions had taken place a new more dynamic society was being built, a society which would transform the world taking up and developing science as a key part of that process.

Paul McGarr



This article is one out of a short series on Science and socialists published in Socialist Worker Review issues 112 to 116 (September 1988 to January 1989):
Paul McGarr: Star wars (Copernicus, Kepler and Galileo)
Andy Wilson: The core of Newton
Mike Simons: Darwin’s new dawn
Duncan Blackie: It’s all relative (Einstein)
Malcolm Povey: The science factory (science and scientists in society)

Sidst opdateret 8.6.2016