Christian de Duve

"The cost of our success is the exhaustion of natural resources, leading to energy crises, climate change, pollution, and the destruction of our habitat. If you exhaust natural resources, there will be nothing left for your children. If we continue in the same direction, humankind is headed for some frightful ordeals, if not extinction."

"We know that once we stop learning and call ourselves learned, we become useless members of the scientific society."

"We have access to practical, ethical and scientifically established methods of birth control. So I think that is the most ethical way to reduce our population."

"The living world has become impoverished. Species are being lost every day. Energy and other resources are nearing exhaustion. The environment is deteriorating. Pollution is everywhere. Climate is changing. Natural balances are threatened."

"life is either a reproducible, almost commonplace manifestation of matter, given certain conditions, or a miracle. Too many steps are involved to allow for something in between."