We only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet.

…only in the few universes that are like ours would intelligent beings develop and ask the question: “Why is the universe the way we see it?” The answer is then simple: If it had been any different, we would not be here!

I believe alien life is quite common in the universe, although intelligent life is less so. Some say it has yet to appear on planet Earth.

If this is the only planet on which not only life, but intelligent life, has arisen, that would be very unusual.

I won't eat anything that has intelligent life, but I'd gladly eat a network executive or a politician.

It is surely unreasonable to credit that only one small star in the immensity of the universe is capable of developing and supporting intelligent life. But we shall not get to them and they will not come to us.