To live in the hearts we leave behind is to live forever.

We are alive and we resonate with idea of life elsewhere, but only careful accumulation and assessment of the evidence can tell us whether a given world is inhabited.

If you want to save your child from polio, you can pray or you can inoculate. ... Choose science.

The suppression of uncomfortable ideasmay be common in religion and politics, but it is not the path to knowledge; it has no placein the endeavor of science.

Life is profligate, blind at this level unconcerned with notions of justice. It can afford to waste multitudes.

Observation: there was absolutely nothing to see on Venus. Conclusion: it must be covered with life.

Advances in medicine and agriculture have saved vastly more lives than have been lost in all the wars in history.

Imagination will often carry us to worlds that never were. But without it we go nowhere.

Has there ever been a religion with the prophetic accuracy and reliability of science? . . . No other human institution comes close.