“You have to know the past to understand the present.”

“Books, purchasable at low cost, permit us to interrogate the past with high accuracy; to tap the wisdom of our species; to understand the point of view of others, and not just those in power; to contemplate--with the best teachers--the insights, painfully extracted from Nature, of the greatest minds that ever were, drawn from the entire planet and from all of our history. They allow people long dead to talk inside our heads. Books can accompany us everywhere. Books are patient where we are slow to understand, allow us to go over the hard parts as many times as we wish, and are never critical of our lapses. Books are key to understanding the world and participating in a democratic society.”

“The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. In a cosmic perspective, most human concerns seem insignificant, even petty. And yet our species is young and curious and brave and shows much promise. In the last few millennia we have made the most astonishing and unexpected discoveries about the Cosmos and our place within it, explorations that are exhilarating to consider. They remind us that humans have evolved to wonder, that understanding is a joy, that knowledge is prerequisite to survival. I believe our future depends on how well we know this Cosmos in which we float like a mote of dust in the morning sky.”

“Arguments from authority carry little weight – authorities have made mistakes in the past. They will do so again in the future. Perhaps a better way to say it is that in science there are no authorities; at most, there are experts.”

“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.”

“We have designed our civilization based on science and technology and at the same time arranged things so that almost no one understands anything at all about science and technology. This is a clear prescription for disaster”

“If we are to send people, it must be for a very good reason - and with a realistic understanding that almost certainly we will lose lives. Astronauts and Cosmonauts have always understood this. Nevertheless, there has been and will be no shortage of volunteers.”