Whatever system of governance is eventually adopted, it is important that it carries the people with it. We need to convey the message that safeguarding our common property, humankind, will require developing in each of us a new loyalty: a loyalty to mankind. It calls for the nurturing of a feeling of belonging to the human race. We have to become world citizens.

Let me remind you that nuclear disarmament is not just an ardent desire of the people, as expressed in many resolutions of the United Nations. It is a legal commitment by the five official nuclear states, entered into when they signed the Non-Proliferation Treaty.

But the nuclear powers still cling tenaciously to their weapons.

I saw science as being in harmony with humanity.

The most terrifying moment in my life was October 1962, during the Cuban Missile Crisis. I did not know all the facts - we have learned only recently how close we were to war - but I knew enough to make me tremble.

Indeed, the whole human species is endangered, by nuclear weapons or by other means of wholesale destruction which further advances in science are likely to produce.

The cold war is over, but cold war thinking survives.