Skip to main content
Ages 13+
Under 13
Couple dressed in part clothes, asleep on couch

In This Beautiful Letter, Richard Dawkins Describes the Scientific Evidence of Love


Dawkins describes love from the lens of evidence in a letter to his ten-year-old daughter.

When his daughter turned 10, evolutionary biologist Richard Dawkins wrote her a simple and thoughtful letter about “why we know what we know”. In his particular tone ––always charming and brilliant–– the father stresses the importance of evidence before blind belief, and the “good and bad reasons for believing”, which is now part of his book of essays entitled A Devil’s Chaplain, published in 2004.

Dear Juliet:

Now that you are ten, I want to write to you about something that is important to me. Have you ever wondered how we know the things that we know? How do we know, for instance, that the stars, which look like tiny pinpricks in the sky, are really huge balls of fire like the Sun and very far away? And how do we know that the Earth is a smaller ball whirling round one of those stars, the Sun?

The answer to these questions is ‘evidence’. Sometimes evidence means actually seeing (or hearing, feeling, smelling…) that something is true. Astronauts have travelled far enough from the Earth to see with teir own eyes that it is round. Sometimes our eyes need help. The ‘evening star’ looks like a bright twinkle in the sky but with a telescope you can see that it is a beautiful ball—the planet we call Venus. Something that you learn by direct seeing (or hearing, or feeling…) is called an observation. […]

The way scientists use evidence to learn about the world is much cleverer and more complicated than I can say in a short letter. But now I want to move on from evidence, which is a good reason for believing something, and warn you against three bad reasons for believing anything. They are called ‘tradition’, ‘authority’ and ‘revelation’.

Here Dawkins continues warning her daughter about the three “bad reasons to believe anything”, particularly applied to religion. But what follows is perhaps one of the most moving ways to talk about love because it deals with “scientific evidence”, which is seldom if ever associated with it.

People sometimes say that you must believe in feelings deep inside, otherwise you’d never be confident of things like ‘My wife loves me’. But this is a bad argument. There can be plenty of evidence that somebody loves you. All through the day when you are with somebody who loves you, you see and hear lots of little tidbits of evidence, and they all add up. It isn’t a purely inside feeling, like the feeling that priests call revelation. There are outside things to back up the inside feeling: looks in the eye, tender notes in the voice, little favors and kindnesses; this is all real evidence.

Inside feelings are valuable in science too, but only for giving you ideas that you later test by looking for evidence. A scientist can have a ‘hunch’ about an idea that just ‘feels’ right. In itself, this is not a good reason for believing something. But it can be a good reason for spending some time doing a particular experiment, or looking in a particular way for evidence. Scientists use inside feelings all the time to get ideas. But they are not worth anything until they are supported by evidence.

What can we do about all this? It is not easy for you to do anything, because you are only ten. But you could try this. Next time somebody tells you something that sounds important, think to yourself: ‘Is this the kind of thing that people probably know because of evidence? Or is it the kind of thing that people only believe because of tradition, authority or revelation? And, next time somebody tells you that something is true, why not say to them: ‘What kind of evidence is there for that?’ And if they can’t give you a good answer, I hope you’ll think very carefully before you believe a word they say.

Your loving


Related Articles