Even through your hardest days, remember we are all made of stardust.

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

The Apollo pictures of the whole Earth conveyed to multitudes something well known to astronomers: On the scale of the worlds - to say nothing of stars or galaxies - humans are inconsequential, a thin film of life on an obscure and solitary lump of rock and metal

We are the first species to have taken our evolution into our own hands.

Knowing a great deal is not the same as being smart; intelligence is not information alone but also judgement, the manner in which information is coordinated and used.

Better by far to embrace the hard truth than a reassuring fable. If we crave some cosmic purpose, then let us find ourselves a worthy goal.

It means nothing to be open to a proposition we don't understand.