Present global culture is a kind of arrogant newcomer. It arrives on the planetary stage following four and a half billion years of other acts, and after looking about for a few thousand years declares itself in possession of eternal truths. But in a world that is changing as fast as ours, this is a prescription for disaster. No nation, no religion, no economic system, no body of knowledge, is likely to have all the answers for our survival. There must be many social systems that would work far better than any now in existence. In the scientific tradition, our task is to find them.
Carl SaganIndeed the reasoned criticism of a prevailing belief is a service to the proponents of that belief; if they are incapable of defending it, they are well advised to abandon it. This self-questioning and error-correcting aspect of the scientific method is its most striking property.
Carl SaganRecent research shows that many children without enough to eat wind up with diminished capacity to understand and learn (“cognitive impairment” ). Children don't have to be starving for this to happen. Even mild undernourishment — the kind most common among poor people in America — can do it.
Carl Sagan