The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us.

Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us.

…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!

Perhaps we've never been visited by aliens because they have looked upon Earth and decided there's no sign of intelligent life.

I'm sure the universe is full of intelligent life. It's just been too intelligent to come here.

I think that it would be unwise of us not to believe that there is life outside of us, intelligent life. And so I do believe in aliens.