The Limits of Reason

One of the things that seems constantly to take people by surprise is that reason is no guarantee of truth. We are continually being told that the validity of one position, and the invalidity of another, is bound to be admitted by all men willing to consider those positions in the light of reason.

A moment's consideration shows that this is far from being the case.

Aristotle, for example, was of of the view that the spermatozoa of black men was itself black. This belief was perfectly reasonable but completely untrue. It doesn't, or course, prove that Aristotle never came across a black man (though it does, on balance, prove that a black man never came across him), but it may equally well be taken to demonstrate that, even in the ancient world, a black man could spot a sucker when he saw one.

More problematic, and less easily verifiable is Voltaire's proposition that 'it is infinitely more useful in a civilised socirty to have even a bad religion than none at all' because 'it is obvious that the sanctity of oaths is necessary, and that we must have confidence rather in those who think a false oath will be punished, than in those who think that they can take a false oath with impunity.' (see Voltaire, Dictionnaire philosophique, sv Athée, Athéisme).

This too, seems a perfectly rational point of view, though it's the sort of thing that scandalises that champion of enlightened atheism, Bishop Richard Holloway.

For over one thousand years, all educated men subscribed to the Ptolemaic system of the universe which posited a celestial arrangement in which the stars were fixed entities in the rotating shell of a heaven with a complex system of crystal tubes along which the planets raced tunefully like brightly coloured balls in in an interplanetary marble run.

It all seems so much nonsense to modern man, of course, but Shakespeare wasn't the only acknowledged genius to take it for granted.

Nevertheless, it was, for a long time, commonly held that mediaeval man believed that the world was flat, and no doubt many did, just as many of its readers still think that The Sun is a source of general illumination.

The theory that the earth was a sphere was probably advanced as early as the 6th Century BC - or BCE, according to the donnish system of dating.

Plato and Aristotle certainly subscribed to the theory that the earth was spherical, but it was the Hellenistic philosopher Eratosthenes, known to his friends as B++, who, proved it geometrically by measuring the angle made at noon on the day of the summer solstice by the shadows of two upright sticks placed 500 miles apart.

Brilliant.

It was Eratosthenes, too, who devised the first armillary sphere, which subsequently evolved to model the intricacies of the Ptolemaic universe. The system was complex, but it was, in its way, beautiful, and it was generally held to testify to the glory and the grandeur of God.

So it is hardly surprising that when Kepler, Copernicus and Galileo began to posit an alternative system they met with considerable resistance. This was not only because man has generally found it more reasonable to believe that the established consensus is correct than what a particular individual claims to have seen through an unusual combination of lenses suspiciously like those used in a pair of spectacles - but also because a system which now appears hideous and unweildly seemed, at the time, and to the unassisted eye, the embodiment of reason and beauty.

The illusions engendered by the romantic cult of the genius have tended to obscure the fact that in nine cases out of ten, the scientific genius concerned has been primarily a genius for observation, and only secondarily for original thought. Such was the case with Galileo Galilei, whose theory as to the movement of the earth depended entirely on the use of a telescope - which the Tuscan seer did not himself invent. The cult of genius also obscures how unreasonable its heroes can be. Galileo, for example, was an arrogant, hot-tempered and vituperative little man who may reasonably be said to have set back the acceptance of his scientific work by serious defects of character and temperament.

Most reasonable people will admit that, where they are not rendered unattractive by bad manners, the views of scientists on subjects outside their competence are harmless, if not charming - rather like the opinions expressed by sports personalities on international affairs or by actors on the subject of morality.

More serious is the way in which scientific ideas have been adopted by self-proclaimed scientific rationalists to provide the basis for heartless and inhuman ideas.

Charles Darwin always refused to speculate in broad terms about the general consequences of his theory for politics, culture and religion, but this did not prevent a host of lesser men from filling the vacuum and using his theories to justify racism, sexism, discrimination, persecution, compulsory euthanasia, enforced sterilisation and genocide.

There was even a German Balt called Reinhold Seeberg who, in the years running up to the First World War advanced what one German historian has called a sub-lutheran 'theology of German Imperialism'. Professor Seeberg's 'God' was, like Odin, a god of strife, who tried and tested the nations in battle. Although an academic, Seeberg volubly championed the German cause in the First World War, and petitioned the imperial government to annex large tracts of Eastern Europe; he never reconciled himself to the Versailles Treaty; he regarded the Weimar Government as the tool of international capitalism; and he welcomed the rise to power of Adolf Hitler as the breaking of a new dawn.

'War' Seeberg maintained, 'is the great judgment of universal history. Some nations rise and some nations fall; the judgment of history is just.' For Seeberg, German defeat in the Great War was no ironic illustration of the proposition because, like many others, he subscribed to the toxic view that the German army had not been defeated in the field, but had been betrayed by an enemy within - Jews, Bolveshiks, or worst of all, Jewish Bolsheviks.

It was Seeberg who composed the elegant latin epigram for the War Memorial to the Graduates of Berlin University which reads 'Invictis Victi Victuri' which, though superficially delphic, is usually translated as 'To the Unconquered from the Conquered who will in time Conquer.'

It must all have seemed quite reasonable at the time.