Dear Mr. Blodgett, thank you for your letter; I am flattered by your interest in my book. Here is a brief statement of encouragement, as you requested. Let me know whether this is suitable:

The advance of technology, together with entirely natural but underestimated catastrophic risks, have created a situation in which the aggregate risk of global catastrophe, when computed over some reasonable time period (say, several decades), though impossible to quantify, cannot be reckoned trivial. Among the natural risks are asteroid collisions and pandemics (not to mention tsunamis and even, as we now know, hurricanes); among the technology-based but accidental, the possibility of a strangelet disaster in the high-energy research accelerators at Brookhaven and CERN, runaway nanotechnology, superintelligent robots, and, of course, global warming, of which the most ominous form would be abrupt rather than gradual such warming. Deliberate technology-based disaster possibilities include bioterrorism using genetically altered pathogens and nuclear and cyber attacks.

These catastrophic risks present in the first instance difficult analytic and psychological questions, such as how to apply cost-benefit analysis, risk assessment, and cognate evaluative techniques under conditions of profound uncertainty, and how to motivate responses to merely probabilistic harms, which the human kind seems largely incapable of taking seriously. The risks also present challenges to conventional thinking about civil liberties, about politics and public policy, and about education, the scientific illiteracy of most Americans having been underscored by the recent debate over the teaching of "intelligent design."

Very truly yours, Richard A. Posner