The scientist should treasure the riddles he can't solve, not explain them away at the outset.

When we imagine our Universe to be just one out of a multitude of possible worlds we devalue this world, the one we see, the one we should be trying to explain.

One of the striking features of the form of globalisation that has now been established is that it is based on the premise that goods and even capital should be free to roam but labour must remain imprisoned within the nation state.

The Amazon is not just a set of trees. It is a set of 25 million people. If we don't create real economic opportunities for them, the practical result is to encourage disorganized economic activities that results in the further destruction of the rain forest.

In my view, a political vision is not a grab-bag of discrete problems and solutions. It is the visionary anticipation of a direction.

In a world of democracies, in a world where the great projects that have set humanity on fire are the projects of the emancipation of individuals from entrenched social division and hierarchy; in such a world individuals must never be puppets or prisoners of the societies or cultures into which they have been born.