When you think you know something: that is a most perfect barrier against learning.

Then, as his planet killed him, it occurred to Kynes that his father and all the other scientists were wrong, that the most persistent principles of the universe were accident and error.

I'm going to rub your faces in things you try to avoid. I don't find it strange that all you want to believe is only that which comforts you. How else do humans invent the traps which betray us into mediocrity? How else do we define cowardice?

The problem of leadership is inevitably: Who will play God?" Muad'Dib

Men always fear things which move by themselves.

You aren't thinking or really existing unless you're willing to risk even your own sanity in the judgement of your existence.

If all those around you believe some particular thing, you will soon be tempted to share in that belief.