I would be very ashamed of my civilization if we did not try to find out if there is life in outer space.

If we can't think for ourselves, if we're unwilling to question authority, then we're just putty in the hands of those in power.

Ask courageous questions. Do not be satisfied with superficial answers.

At the heart of science is an essential balance between two seemingly contradictory attitudes-an openness to new ideas, no matter how bizarre or counterintuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense.

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

The universe is a pretty big place. If it's just us, seems like an awful waste of space.

The vast distances that separate the stars are providential. Beings and worlds are quarantined from one another. The quarantine is lifted only for those with sufficient self-knowledge and judgment to have safely traveled from star to star.