'... let us recall the well-known statement of a university professor in the
                   Republic of the Massagetes: "Not the faculty but His Excellency the General
                   can properly determine the sum of two and two."'
                                                                                                    - Hermann Hesse

The world is a dangerous place right now. Politicians encourage a new version of the Cold War's nuclear arms race, more dangerous now because there are more players in the game. Greed overrides prudence in the rush to burn our last resources of fossil fuels, leading the planet ever closer to an irreversible tipping point of climate change. And relentless human population pressure drives more of our fellow species to extinction.

Those are opinions. But the facts on which they are based are not.

There are two ways to react to the situation. We may wait passively for the Horsemen of the Apocalypse to come and do their work. Or we may put our trust in tried methods of reasoning, observation, and experiment to look for ways to alleviate things.