One of my favorites quotes.
From a TV show (by Dr. Who's Davies no less), though I actually know it best from this song.
You, are becoming Gods. There's a new master of creation, and it's you! Unraveled DNA, and at the same time you're cultivating bacteria strong enough to kill every living thing! Do you think you are ready for that much power? You lot? You lot? Cheeky bastards. You're running around science like kids with guns, creating a new world, while the world you've got is stinking, but, hands up, hands up anyone who thinks you've got it right. Yeah, there's always one. I can see you. If you want the position of God then take the responsibility.
-Christopher Eccleston as "Stephen Baxter" in 2003's The Second Coming.
Yes, too often we ask if we can do something when the better question is, "should we?"