I knew I wanted to be a scientist when I realized that science was not about the truth. I know that this statement requires some clarification; it might help if I told you how I came to this realization. There is nothing particularly special about my story except, perhaps, for how it began.

Credit: BERTOLD WERKMANN/SHUTTERSTOCK

In the early 2000s, I was at work at a recruitment company in London when I got a phone call. It was my mother: she told me that my sister had had a brain haemorrhage, and was critically ill. I ran home, packed a bag and took a train to the hospital, arriving just as my sister came out of surgery. She was in a bad way, the doctors said. The operation had been complicated and there was no way of knowing if she would ever wake up. She did not regain consciousness for many days.

I stayed at the hospital for the entire time, and sat by her bed through the days and nights. I knew that I wasn't doing anything useful, but I couldn't sleep and the hospital room seemed to be as good a place to be awake as any. I spent most of that time thinking. I was upset. Why could no one tell us what was going on? I assumed that some people, somewhere, knew a great deal about the brain and how it worked. I thought that the problem must have to do with the distribution of the relevant information — if there were more neurologists and psychologists, then more could be done for people who were ill. It seemed to me that the job that I had been doing for five years was not as important as this sort of aspiration. I was earning good money, but I had started to feel that the job was repetitive and boring. And now I began to feel that it was rather a pointless thing to be doing with my life.

Change of tack

My sister began to get better, and after about two weeks she was allowed to go home. I went back to my life in London, relieved but determined. I decided to take a master's degree in neuropsychology, with the aim of becoming a clinical psychologist. But I did not become a clinical psychologist. I became a scientist instead — by accident. How did this happen?

There are four stages on the road to becoming a scientist, and I remember them all.

To begin with, you simply want someone in the know to tell you the truth. You read textbooks and attend lectures, and are overawed by the immensity of it all but struck by how neatly everything fits together. You do a few simple experiments in your lab, and you get exactly the results that are expected. There seem to be answers to all of your questions, and you feel that if you read enough textbooks and attend enough lectures then you will understand all there is to understand. This is the stage I was at when I finished my first undergraduate degree, and what I was expecting to find when I went back to do my master's.

Conflicting stories

If I am lucky, I will spend the rest of my life finding new things that I will never quite be able to explain.

The second stage begins when you realize that scientists frequently disagree with each other about what is true. This stage is disturbing, and is caused by taking the business of writing essays and papers seriously. Typically, you will be given a question along the lines of, “What function does Broca's area of the brain serve?” To answer it, you start by reading a long paper by Professor X, who sets out his theory in convincing detail. You think, “Of course, how obvious. It controls the processing of syntax — how could anyone think otherwise?” Next, you read an equally long and detailed review paper by Professor Y, who takes a contrary view, and you think, “Hmm. Professor Y makes some very good points. Perhaps Professor X doesn't know what he's talking about after all”. And then on you go to Professor Z, and utter confusion. One of them must be telling the truth, but which one? So you write your essay, describing the contrasting theories of X, Y and Z and conclude: “Opinion is divided — more research is necessary.” This is the stage I was at when I finished my master's degree. I decided that maybe I could do some of that research, so I started a PhD.

The third stage of becoming a scientist begins with the realization that nobody knows the truth. This stage is absolutely terrifying, and is caused by doing research. When I started running real experiments, collecting data and testing my ideas against those data, I came to realize that things were not as clear cut as they had seemed from the papers that I had been reading. Sometimes things did not work out as predicted by any of the theories that I knew about. There was always something that could not be explained. I found this troubling, and began to doubt my work. Luckily, I had a very supportive supervisor.

When you start doing science at the PhD level, you begin to work and socialize with real scientists — occasionally the very scientists who wrote the papers that so impressed you during your studies. Once you become a professional scientist, these people are usually happy to let you in on an important trade secret: nobody is really sure of anything. A scientific paper is just one cut and polished facet of a bigger, uglier stone. Behind the beautiful graphs and whip-smart arguments lies a tangled mass of doubts, conjectures and anomalies. Pulling any loose thread is usually enough to make the paper lose its shape. The most important thing my supervisor taught me was that this is not a bad thing.

Better and better

Some scientists are lucky enough to pass through a fourth stage. This is when you realize that science is not about finding the truth at all, but about finding better ways of being wrong. The best scientific theory is not the one that reveals the truth — that is impossible. It is the one that explains what we already know about the world in the simplest way possible, and that makes useful predictions about the future. When I accepted that I would always be wrong, and that my favourite theories are inevitably destined to be replaced by other, better, theories — that is when I really knew that I wanted to be a scientist.

A theory can never be perfect: the best it can be is better than the theory that went before. I want to come up with better theories about how the brain works. If I can do this, then someone else can use my ideas to come up with something even better. As theories improve, we are able to make more useful predictions about how things might work in the real world, and from those predictions we can develop better treatments. I want to be part of this progression. This means that, if I am lucky, I will spend the rest of my life finding new things that I will never quite be able to explain.

So there it is. My interest in the brain is pragmatic, rather than curious. I never really wanted to become a scientist. But I became one eventually, because I had to.