“In college, in the early 1950s, I began to learn a little about how science works, the secrets of its great success, how rigorous the standards of evidence must be if we are really to know something is true, how many false starts and dead ends have plagued human thinking, how our biases can colour our interpretation of evidence, and how often belief systems widely held and supported by the political, religious and academic hierarchies turn out to be not just slightly in error, but grotesquely wrong.”

“There are many hypotheses in science that are wrong. That's perfectly alright; it's the aperture to finding out what's right. Science is a self-correcting process. To be accepted, new ideas must survive the most rigorous standards of evidence and scrutiny.”

“The Cosmos extends, for all practical purposes, forever. After a brief sedentary hiatus, we are resuming our ancient nomadic way of life. Our remote descendants, safely arrayed on many worlds throughout the Solar System and beyond, will be unified by their common heritage, by their regard for their home planet, and by the knowledge that, whatever other life may be, the only humans in all the Universe come from Earth. They will gaze up and strain to find the blue dot in their skies. They will love it no less for its obscurity and fragility. They will marvel at how vulnerable the repository of all our potential once was, how perilous our infancy, how humble our beginnings, how many rivers we had to cross before we found our way.”

“Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works.”

“In the way that scepticism is sometimes applied to issues of public concern, there is a tendency to belittle, to condescend, to ignore the fact that, deluded or not, supporters of superstition and pseudoscience are human beings with real feelings, who, like the sceptics, are trying to figure out how the world works and what our role in it might be. Their motives are in many cases consonant with science. If their culture has not given them all the tools they need to pursue this great quest, let us temper our criticism with kindness. None of us comes fully equipped.”

“The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge, and there's no place for it in the endeavor of science. We do not know beforehand where fundamental insights will arise from about our mysterious and lovely solar system. The history of our study of our solar system shows us clearly that accepted and conventional ideas are often wrong, and that fundamental insights can arise from the most unexpected sources.”

“The best way to avoid abuses is for the populace in general to be scientifically literate, to understand the implications of such investigations. In exchange for freedom of inquiry, scientists are obliged to explain their work. If science is considered a closed priesthood, too difficult and arcane for the average person to understand, the dangers of abuse are greater. But if science is a topic of general interest and concern - if both its delights and its social consequences are discussed regularly and competently in the schools, the press, and at the dinner table - we have greatly improved our prospects for learning how the world really is and for improving both it and us.”