In 1947 I defended my thesis on nuclear physics, and in 1948 I was included in a group of research scientists whose task was to develop nuclear weapons.

Our country, like every modern state, needs profound democratic reforms. It needs political and ideological pluralism, a mixed economy and protection of human rights and the opening up of society.

Both now and for always, I intend to hold fast to my belief in the hidden strength of the human spirit.

A country which does not respect the rights of its own citizens will not respect the rights of its neighbours

Do not trust governments more than governments trust their own people.

Intellectual freedom is the only guarantee of a scientific - democratic approach to politics, economic development, and culture.

Profound insights arise only in debate, with a possibility of counterargument, only when there is a possibility of expressing not only correct ideas but also dubious ideas.

You can't sit on two chairs at once.

I could not stop something I knew was wrong and terrible. I had an awful sense of powerlessness.

I regard the death penalty as a savage and immoral institution that undermines the moral and legal foundations of society.

Profound thoughts arise only in debate, with a possibility of counterargument, only when there is a possibility of expressing not only correct ideas, but also dubious ideas.

The problem is not lack of leadership, the problem is lack of good leadership

As J. B. S. Haldane said when asked what evidence might contradict evolution, 'Fossil rabbits in the Precambrian.

PERFECTION, n. An imaginary state of quality distinguished from the actual by an element known as excellence; an attribute of the critic.

Fateful moments tend to evoke grandeur of speech, especially in French.

There's a lot of things that need to change, a lot of different issues that need to be addressed.

I'm interested in astrology and astronomy.

When you find you don't like a character, you just type four letters and he's dead.

In Latin America in general, it's very important that Christianity not be simply a thing of reason, but also of the heart.

We all love best not those who offend us least, but those who make it most easy for us to forgive them.

I mention my age because I find people in this country - women, not men, of course - women are so troubled by their age. There's a culture of youth, and it's a phony culture.