I saw an item on Digg about 250 scientists who were asked what they wish everyone could learn about science. My favorite answer is this:
I would teach the world that scientists start by trying very hard to disprove what they hope is true. When they fail, they have a good reason for believing what they hope is true, and can even convince others of its truth. A scientist always acknowledges the possibility of error, and is less likely to be mistaken than one who always claims to be right.
– Antony Hoare Senior researcher at Microsoft Corporation