The difference between physics and metaphysics is not that the practitioners of one are smarter than the practitioners of the other. The difference is that the metaphysicist has no laboratory.

We are, in the most profound sense, children of the Cosmos.

The Earth is a very small stage in a vast cosmic arena.

If chimpanzees have consciousness, if they are capable of abstractions, do they not have what until now has been described as 'human rights'? How smart does a chimp have to be before killing him constitutes murder?

But nature is always more subtle, more intricate, more elegant than what we are able to imagine.

For a long time the human instinct to understand was thwarted by facile religious explanations.

Virtually every major technological advance in the history of the human species - back to the invention of stone tools and the domestication of fire - has been ethically ambiguous.