The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge, and there's no place for it in the endeavor of science. We do not know beforehand where fundamental insights will arise from about our mysterious and lovely solar system. The history of our study of our solar system shows us clearly that accepted and conventional ideas are often wrong, and that fundamental insights can arise from the most unexpected sources.

Science is more than a body of knowledge. It's a way of thinking: a way of skeptically interrogating the universe.

We are one species. We are starstuff.

'In his celebrated book, 'On Liberty', the English philosopher John Stuart Mill argued that silencing an opinion is "a peculiar evil." If the opinion is right, we are robbed of the "opportunity of exchanging error for truth"; and if it's wrong, we are deprived of a deeper understanding of the truth in its "collision with error." If we know only our own side of the argument, we hardly know even that: it becomes stale, soon learned by rote, untested, a pallid and lifeless truth.'

Nature does not always conform to our predispositions and preferences, to what we deem comfortable and easy to understand.

Books are like seeds. They can lie dormant for centuries and then flower in the most unpromising soil.

What an astonishing thing a book is.