If there is one thing that people should do much more of, it's thinking.

Don't get me wrong. A lot of people are not much good at it, and even many of those who are often don't bother to. But being good at something and something being good for you are two different things, as plenty of Saturday afternoon golfers well know. Doing some thinking every so often, even if it's are a long way short of profundity, will do you a lot of good.

When people are trying to work out what they think about something, the best way is to think about as much of it as possible, and not to take any prepackaged opinions from anyone else. Go back as far as you possibly can when you're thinking about something, establish some first principles and build upwards from there. Maybe you'll end up exactly where you were previously, but maybe you'll realise that your previous views were wrong. If you realise that, and have the courage to change your mind, you are being far braver and far more honest with yourself than most people ever are.

Realising that your previous views were wrong is one of the hardest things about life. It means doing two things that people are very bad at. The first is saying, I Was Wrong. Nobody wants to look stupid, and changing your mind often feels like an admission of an error, and can make people feel like idiots. The second is changing your mind about something. This may mean alienating yourself from people who hold a similar view. If you belong to a group brought together by its common beliefs – a religion or political party, for example – this can be a very hard thing to do. It will also mean that people will think that you are merely blowing in the wind. And if you point out that changing your mind means that you are thinking about things, rather than just following your prejudices, people still think that this is the result of some weakness of character.

Debate involves each side explaining its views on an issue, and then justifying them. There are two reasons for debate. The first is to try to sway those who have not made up their minds. The second is to convince those who have made up their minds in an opposite direction from your own that they are wrong. In both cases, what you're really trying to do is convince people that your reasoning is not only better than theirs, but better than anyone else's. This is where it's important to have done your own thinking, because then you know what the logic behind your point of view is. Only then can you evaluate whether someone else's logic is better.

In any event, it is a really nice feeling to have worked something out. It's also quite obvious which people have done this, because they are the ones who sound more convincing when they are involved in debates. People may find that the half-formed ideas that they have accumulated instinctively over the years have some basis, or may find that they don't.

As I have written previously, this should be the role of the education system, rather than having students rote learning, which is what it often comes down to. Curiously, primary schools spend plenty of time getting people to do exercise for its own sake, but every time somebody tries to encourage thinking for its own sake it is discouraged – after all, you can find everything you want on the internet these days, don't you know.

I got on to this topic when I wrote about an effective way of running the judiciary, and realised that this was probably not a process that too many other people have followed. I have also touched on it in talking about people's reasoning in general (twice), and for exams in particular. Abortion is one issue on which people seem to make up their minds before doing any thinking.

So I guess that what I'm doing here is just bringing together many different threads that I've touched on previously.

But how I got on to writing an article to bring these strands together was a very interesting television debate from 1979, about The Life Of Brian. For the good guys was Michael Palin; for the bad guys was the Archbishop of Canterbury. One of the Archbishop's argument was that the movie might cause people to lose their faith. (Obviously, anyone who thinks that this is movie about religion hasn't bothered to watch it properly. But that's a story for another day).

I don't mean to imply that the Archbishop of Canterbury is a bad guy because of his position. He's a bad guy because he doesn't want to let people think for themselves. This was someone who has been a part of a religion for his whole adult life and yet who thinks that other people are so insecure in their faith that they may be turned off it by a two hour movie that is about human stupidity. Perhaps the Archbishop thought that if people were actually to start thinking about their attendance at church each week, they might not go along. Either way, his views demonstrated a real lack of thought.

The world can be a fairly depressing place at times, and the more you think about things, the more depressing it seems. It is depressing, as I noted above. But there is more life than short-term happiness. I would compare it to moving out of home at 18, living in messy student flats and making your own mistakes rather than living more comfortably at home and having your parents making all of your decisions.

Someone once said, 'give me liberty or give me death', and it seems to me that this is the same thing. The sense of awareness that comes from thinking, really, genuinely thinking, is something that is far more important than any sense of melancholy that may result. As I noted above, even if you're not much good at it, it will do you a lot of good.