terça-feira, 13 de julho de 2010

Two razors, two Englishmen and some sense of humor

History is made of ironies.

It is curious that the Latin expression “entia non sunt multiplicanda praeter necessitatem”, so often used by scientists in the search for ever simpler explanations, was first written by a medieval English Franciscan monk, William of Ockham.

The principle now known as Ockham’s razor says that variables must not be added beyond necessity and counsels that, if everything is equal, the simplest explanation is usually the correct one. In science it seems evident that this should be the case and I wouldn’t want to contradict it in any way. For practical reasons comes in very handy (sorry for the tautology) that we should always use this razor.

Although extremely useful, Ockham’s razor is not applicable to everything we come across. What should you do if all possible explanations are equally simple? In this case, which razor shall we use?

The first time I thought about this I felt I was going into freefall. We were never taught which criteria to use when facing, ceteris paribus, two equally simple and plausible solutions. Here, Ockham’s razor, as sharp as it may be, can’t do the job. Before finding a possible solution, let’s jump five centuries, from the medieval ages into the middle of the 19th century.

In November 1859 the most amazing book about science of all times was published. The reading of which should be compulsory for all biology based courses. It is shocking to find colleagues that call themselves biologists and yet have never read even one sentence of the Origin. I don’t even dare to ask how many PI’s in our beloved institute have not read it. On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, was more than a stroke of genius. It is the result of hard labour by a reserved scientist, one not much given to adventures. This is one of the characteristics that amazed me most about Darwin’s personality: his modesty, almost blurring into lack of courage, where resistance to dramatic changes lived alongside the theory of evolution by natural selection. He turned biology upside down, shedding light on a world that had just started to have a purely empirical explanation basis. It is beautiful to see Mankind thinking about the world, explaining and understanding nature without turning to easy and so many times false, explanations.

Sometimes we may ask ourselves “if it hadn’t been for him...”.

Surely someone else would appear. Wallace came to almost the same conclusions independently. Only time would tell who else to credit.

The awe comes not from the thought that could be someone else, but from the fact that it was not someone else!

The young naturalist from Shrewsbury was always an underdog. He doesn’t conform to any of our stereotypes of a genius: not to Einstein, to Linnaeus, to Newton and even less to Galileo or Aristotle. Darwin was the most modest and shiest of them all, a simple British citizen of the 19th century: competent, hard working, a solid member of society and a well connected one. It was outrageous that one of them, a gentleman, was showing to the world that we are not superior to anyone from a different culture or society: that we all have the same origin. It was a common person that changed the way that we see ourselves. We are all brothers and no society or people are above others, neither in gender, colour or species. We all evolved together and, in this global dance, so many and so diverse life forms arose.

Darwin told a friend in 1884 that to publish his theory was “like confessing a murder”. This expression is unthinkable for any other revolutionary of science, but Darwin is like all of us, he was one amongst equals. He was a genius, yet closer to us than other incomprehensible eccentric figure from Physics, Mathematics, Chemistry, or any other field of show biz.

It may not be very intuitive, but is certainly funnier, to think that it was amongst the Victorian aristocratic classes that the most brilliant and subversive description for the origin of Life arose. Even so, and because it was so improbable, Darwin presented the most curious solution. To imagine millions of species sharing a common ancestor, and conceive that all of these forms have mutually modified each other over billions of years, giving rise to all this beauty that surround us, is by far more amusing than to believe in a static and immutable world.

Darwin observed, compiled and integrated a mountain of facts to present the conclusions that he wrote in the Origin of Species. Even at that time there was no equality of circumstances, yet it was the funnier solution that prevailed. If we have this principle in mind, we can add another razor to our epistemological tool bag proclaiming that, if all solutions are equally plausible and simple, choose the funniest.

At least, and until proven wrong, we will have a droller new world.


In Quinta Grande - The Newsletter of the Instituto Gulbenkian de Ciência - Summer 2010 - Issue 6

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