Sustainability is living on nature's income rather than living on its capital.

Our planet doesn't seem to be the result of anything very special

I would recommend that skeptics devote even more effort than they do now to understanding the reasons why so many people want or need to believe.

Everything that is not forbidden is compulsory.

The persistence of erroneous beliefs exacerbates the widespread anachronistic failure to recognize the urgent problems that face humanity on this planet.

As a theoretical physicist, I feel at once proud and humble at the thought of the illustrious figures that have preceded me here to receive the greatest of all honors in science, the Nobel prize.

Enthusiasm is followed by disappointment and even depression, and then by renewed enthusiasm.