I think if we ever reach the point where we think we thoroughly understand who we are and where we came from, we will have failed.

Even today the most jaded city dweller can be unexpectedly moved upon encountering a clear night sky studded with thousands of twinkling stars. When it happens to me after all these years it still takes my breath away.

There is a reward structure in science that is very interesting: Our highest honors go to those who disprove the findings of the most revered among us. So Einstein is revered not just because he made so many fundamental contributions to science, but because he found an imperfection in the fundamental contribution of Isaac Newton.

In science it often happens that scientists say, "You know that's a really good argument; my position is mistaken..."

We are the custodians of life's meaning.

In Italy, the Inquisition was condemning people to death until the end of the eighteenth century, and inquisitional torture was not abolished in the Catholic Church until 1816. The last bastion of support for the reality of witchcraft and the necessity of punishment has been the Christian churches.

In the deepest sense the search for extraterrestrial intelligence is a search for ourselves.