1,131 Quotes by Carl Sagan

Everything not forbidden by the laws of nature, he assured her - quoting a colleague down the hall - is mandatory.

We will know which stars to visit. Our descendants will then skim the light years, the children of Thales and Aristarchus, Leonardo and Einstein.

Birds know, better than humans, not to spoil the nest.

Even if the aliens are short, dour, and sexually obsessed—if they’re here, I want to know about them.

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

El intelecto humano lo debe esencialmente todo a los millones de años que nuestros antecesores pasaron en solitario colgados de los árboles.

Perhaps if one less dragonfly had drowned in the Carboniferous swamps, the intelligent organisms on our planet today would have feathers and teach their young in rookeries. The pattern of evolutionary causality is a web of astonishing complexity; the incompleteness of our understanding humbles us.

It may be that there are kernels of truth in a few of these doctrines, but their widespread acceptancebetokens a lack of intellectual rigor, an absence of skepticism, a need to replace experiments by desires.

So far as I know, childbirth is generally painful in only one of the millions of species on Earth: human beings. This must be a consequence of the recent and continuing increase in cranial volume... Childbirth is painful because the evolution of the human skull has been spectacularly fast and recent.