You will find ambiguity a great ally on your road to power. Give a sign of Slytherin on one day, and contradict it with a sign of Gryffindor the next; and the Slytherins will be enabled to believe what they wish, while the Gryffindors argue themselves into supporting you as well. So long as there is uncertainty, people can believe whatever seems to be to their own advantage. And so long as you appear strong, so long as you appear to be winning, their instincts will tell them that their advantage lies with you. Walk always in the shadow, and light and darkness both will follow.

Many have stood their ground and faced the darkness when it comes for them. Fewer come for the darkness and force it to face them.

Moore's Law of Mad Science: Every eighteen months, the minimum IQ necessary to destroy the world drops by one point.

And someday when the descendants of humanity have spread from star to star, they won’t tell the children about the history of Ancient Earth until they’re old enough to bear it; and when they learn they’ll weep to hear that such a thing as Death had ever once existed!

Every mystery ever solved had been a puzzle from the dawn of the human species right up until someone solved it.

There's something in science like the shine of the Patronus Charm, driving back all sorts of darkness and madness.

That which the truth nourishes should thrive.