Privacy — like eating and breathing — is one of life's basic requirements.

Physics is to mathematics what sex is to masturbation.

Privacy is a luxury; to buy it you need to be able to buy space and fit locks, to switch off the phone and live without fear of dependency on others. Privacy is a peculiarly twentieth-century concept, an artefact of the Western urban middle classes: Before then, only the super rich could afford it, and since the invention of e-mail and the mobile phone, it has largely slipped away.

A book is as private and consensual as sex.

Sometimes those things that attract the most attention to us are the things that afford us the greatest privacy.

Physics is like sex: sure, it may give some practical results, but that's not why we do it.

Americans, in spite of their public declarations of affection, in spite of their miniskirts and bikinis, in spite of their hand-holding on the street and lying on top of each other on the Cambridge Common, prefer their privacy.

In our culture privacy is often confused with secrecy. Open, honest, truth-telling individuals value privacy. We all need spaces where we can be alone with thoughts and feelings - where we can experience healthy psychological autonomy and can choose to share when we want to. Keeping secrets is usually about power, about hiding and concealing information.

I can't think that it would be terrible of me to say — and it is occasionally true — that I need physics more than friends.

Privacy is a type of conversation. Firms should view privacy not as some inconvenient obsession of customers that must be snuck around but more as a way to cultivate a genuine relationship.

If you want to be private you can be private.

It isn't only famous movie stars who want to be alone. Whenever I hear someone speak of privacy, I find myself thinking once again how real and deep the need for such times is for all human beings . . . at all ages.

But she has gathered that Americans, in spite of their public declarations of affection, in spite of their miniskirts and bikinis, in spite of their hand-holding on the street and lying on top of each other on the Cambridge Common, prefer their privacy.

Privacy is something that we maintain for the good of ourselves and others.