Life is about growth and change. When you stop growing, you stop living.

The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny...'

We can’t ignore the economic role of coal, but we also can’t ignore its environmental impact.

In the state of nature, indeed, all men are born equal, but they cannot continue in this equality. Society makes them lose it, and they recover it only by the protection of the laws.