The morality of an act is a function of the state of the system at the time it is performed.

Indeed, our particular concept of private property, which deters us from exhausting the positive resources of the earth, favors pollution.

We can't cure a shortage by increasing the supply.

It is a mistake to think that we can control the breeding of mankind in the long run by an appeal to conscience.

The only thing we can really count on in this uncertain world is human unreliability itself.

Religious reasons, which is no reason. I notice Skeptic had a review of Dennett's book, Darwin's Dangerous Idea. Religious reasons amount to what Dennett terms "skyhooks." Do you believe in skyhooks? I don't.

Every plausible policy must be followed by the question 'And then what?'