What we do with our world, right now, will propagate down through the centuries and powerfully affect the destiny of our descendants. It is well within our power to destroy our civilization, and perhaps our species as well

Carl Sagan

Sagan always said we had the potential to be better, but he was also concerned it was an uphill climb. Where Carlin got angrier with age, I think Sagan would just have been disappointed in us. Especially in the fall back into ignorance and superstition, something else he warned about in The Demon-Haunted World. Every quote you can find from that book is profound, but this one is eerily hard hitting:

“We've arranged a global civilization in which most crucial elements profoundly depend on science and technology. We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.”