Every day we hear opinions and comments about what is going on in the world and we disagree with some of them. We may find ourselves arguing about them and this is not a problem for people who are tolerant of each others point of view. But facts are another matter. Most people are prepared to accept as true the news that they read in the papers, hear on the radio or see on TV. They also tend to believe facts that other people – family, friends, casual acquaintances – tell them. But what if you are reviewing your deeply held beliefs and ask yourself the question: What can you be absolutely sure about?
400 years ago the great French philosopher Descartes asked himself this question and decided to carry out a thought experiment. He would pretend that there was a plot by a demon to deceive him; he would not believe things that he normally took for granted unless he was absolutely sure that they were true. It was a brilliant philosophical starting point and his work laid new foundations for his successors to build on.
Let us for a moment take the same attitude as Descartes and question a few things we have never before doubted. Like him we will suppose there is an evil demon trying to deceive us.
1: ‘The population of the world is about 6 billion.’
Well, I’ve never seen more than 60,000 at a time. Are they saying that for every one person I’ve seen there exist another 100,000? That’s a lot of people. I don’t have to believe it. When I see another crowd they may be the same people, shuffled around somehow by the demon.
2: ‘There’s a city called Toronto on the side of a big lake.’
I’m inclined to believe this because I’ve been there. At least, I thought I’d been there. I got in a plane and it took me somewhere and the people there said it was Toronto; but the demon could have been bribing them.
3: ‘There’s a thing called the internet which links millions of computers all over the world and you can use it to find out the facts about everything.’
OK, I use my home computer to do just that. But all I know is that words and pictures appear on the screen when I fiddle with the keyboard. For all I know some demon is tapping into my phone connection and making it all up. Maybe there is no internet.
Descartes carried this process to its logical conclusion. He knew that all the information received by his brain came through the nerves connected to his eyes, ears, skin, nose and mouth. And the demon could be feeding bogus information along those nerves. So where did that leave him? He now made the statement that remains famous 400 years later:
‘I think, therefore I am’ (‘Cogito, ergo sum’ in the original Latin).
He was sure of that. The demon could not deceive him about the fact that he existed. But he was not sure of anything else.
Now Descartes was a highly intelligent man (a great mathematician who introduced the system of ‘Cartesian’ coordinates (x-y-z axes) to 3D geometry). He realised that the point he had reached was no basis for a normal life. He had to believe in the existence of other people. But he was a man of his times and could see only one way out of the trap in which he was caught: he must believe in a God who would not allow a demon to tamper with his body senses.
The logical process that led Descartes into this philosophical trap known as solecism is still true today. But belief in God is not an acceptable way out of the trap for everyone. Yet how else can they escape? Bertrand Russell, the leading philosopher of the 20th century, did not believe in God and had another solution. He pointed out that that logical process requires you to deny the existence of other people. But this is psychologically impossible for a sane person and must therefore be rejected. No divine assistance is necessary. In his book ‘Human Knowledge’ he tells how he once received a letter from an eminent logician saying she believed in solecism and was surprised that nobody else did. Her surprise surprised Bertrand Russell. Clearly she believed in the existence of other people so she could not sincerely believe in solecism.
I hope that one day people who are prominent in public life (scientists, broadcasters, presenters, clerics, commentators) will see it as a duty to tell us clearly and briefly ‘where they are coming from’ – that is, to publish their fundamental beliefs or their ‘My Credo in a Nutshell’ (acronym ‘mycian’.)