Found in 2 comments on Hacker News
eli · 2012-12-25 · Original thread
MP "You can't compare harms from a legal activity with an illegal one."

Professor Nutt "Why not?"

MP "Because one's illegal."

Professor Nutt "Why is it illegal?"

MP "Because it's harmful."

Professor Nutt "Don't we need to compare harms to determine if it should be illegal?"

MP "You can't compare harms from a legal activity with an illegal one."

http://www.amazon.com/Drugs-Without-Hot-David-Nutt/dp/190686...

glaugh · 2012-09-18 · Original thread
Nutt also wrote a pretty solid book about the data on the harms of various drugs (legal and illegal), and how best to reduce that harm as a society.

http://www.amazon.com/Drugs-Without-Hot-David-Nutt/dp/190686...

edit: Economist review of said book: http://www.economist.com/node/21560223