Nevertheless, (Jefferson) believed that the habit of skepticism is an essential prerequisite for responsible citizenship. He argued that the cost of education is trivial compared to the cost of ignorance, of leaving government to the wolves. He taught that the country is safe only when the people rule.

If the greenhouse effect is a blanket in which we wrap ourselves to keep warm, nuclear winter kicks the blanket off.

The cure for a fallacious argument is a better argument, not the suppression of ideas.

The nuclear arms race is like two sworn enemies standing waist deep in gasoline, one with three matches, the other with five.

The method of science, as stodgy and grumpy as it may seem, is far more important than the findings of science.

My deeply held belief is that if a god of anything like the traditional sort exists, our curiosity and intelligence is provided by such a God. We would be unappreciative of that gift if we suppressed our passion to explore the universe and ourselves.

We are made of star-stuff. Our bodies are made of star-stuff. There are pieces of star within us all.