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

Of course the word chaos is used in rather a vague sense by a lot of writers, but in physics it means a particular phenomenon, namely that in a nonlinear system the outcome is often indefinitely, arbitrarily sensitive to tiny changes in the initial condition

Everything that is not forbidden is compulsory.

Both biological and cultural diversity are now severely threatened and working for their preservation is a critical task.

Superstitions typically involve seeing order where in fact there is none, and denial amounts to rejecting evidence of regularities, sometimes even ones that are staring us in the face.

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

We are driven by the usual insatiable curiosity of the scientist, and our work is a delightful game.