And our small planet, at this moment, here we face a critical branch-point in the history. 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. If we capitulate to superstition, or greed, or stupidity we can plunge our world into a darkness deeper than time between the collapse of classical civilization and the Italian Renaissance.
- Carl Sagan