“We cannot rely on trial-and-error approaches to deal with existential risks… We need to vastly increase our investment in developing specific defensive technologies… We are at the critical stage today for biotechnology, and we will reach the stage where we need to directly implement defensive technologies for nanotechnology during the late teen years of this century… A self-replicating pathogen, whether biological or nanotechnology based, could destroy our civilization in a matter of days or weeks.”