The fact that we have not yet found the slightest evidence for life - much less intelligence - beyond this Earth does… — Arthur C. Clarke Copy Share Image
Shall I not have intelligence with the earth? Am I not partly leaves and vegetable mould myself. — Henry David Thoreau Copy Share Image
Our planet has been around only for four and a half billion years. Let's imagine a planet that has life on it… — Neil deGrasse Tyson Copy Share Image
The issue, as correctly emphasized by Carl Sagan, is the probability of the evolution of high intelligence and an electronic civilization on… — Ernst Mayr Copy Share Image
