"Torture is an impermissible evil. Except under two circumstances. The first is the ticking time bomb. An innocent's life is at stake. The bad guy you have captured possesses information that could save this life. He refuses to divulge. In such a case, the choice is easy."

“Courage is not a quality one normally associates with mathematicians. Yet it should apply to people who work in their attics in secret for seven years without cease on a problem that has eluded the greatest mathematical minds since first proposed in 1637.”

“Science has everything to say about what is possible. Science has nothing to say about what is permissible.”

“When under attack, no country is obligated to collect permission slips from allies to strike back.”

“In an essay 10 years ago, I pointed out that it is utterly logical for polygamy rights to follow gay rights. After all, if traditional marriage is defined as the union of two people of opposite gender, and if, as advocates of gay marriage insist, the gender requirement is nothing but prejudice, exclusion and an arbitrary denial of one's autonomous choices in love, then the first requirement — the number restriction — is a similarly arbitrary, discriminatory and indefensible denial of individual choice.”

“Affluent enviros are all for wind farms, until one is proposed that might mar the serenity of a sail from the crew-necked precincts near Nantucket Sound. Then it's clean energy for thee, not for me.”

“In explaining any puzzling Washington phenomenon, always choose stupidity over conspiracy, incompetence over cunning. Anything else gives them too much credit.”