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 syste… - Carl Sagan

n those cultures lacking unfamiliar challenges, external or internal, where fundamental change is unneeded, novel ideas need not be encouraged. Indeed, heresies can be declared dangerous; thinking can be rigidified; and sanctions against impermissible ideas can be enforced — all without much harm. But under varied and changing environmental or biological or political circumstances, simply copying the old ways no longer works. Then, a premium awaits those who, instead of blandly following tradition, or trying to foist their preferences on to the physical or social Universe, are open to what the Universe teaches.

Natural selection has served as a kind of intellectual sieve, producing brains and intelligences increasingly competent to deal with the laws of nature. This resonance, extracted by natural selection, between our brains and the universe may help explain a quandary set by Einstein: The most incomprehensible property of the universe, he said, is that it is so comprehensible.

For ages men had used sticks to club and spear each other — Anaximander of Miletus used the stick to measure time.