World domination is such an ugly phrase. I prefer to call it world optimisation.

Do not flinch from experiences that might destroy your beliefs. The thought you cannot think controls you more than thoughts you speak aloud. Submit yourself to ordeals and test yourself in fire. Relinquish the emotion which rests upon a mistaken belief, and seek to feel fully that emotion which fits the facts.

A burning itch to know is higher than a solemn vow to pursue truth. To feel the burning itch of curiosity requires both that you be ignorant, and that you desire to relinquish your ignorance.

Trying and getting hurt can't possibly be worse for you than being... stuck.

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.

The police officer who puts their life on the line with no superpowers, no X-Ray vision, no super-strength, no ability to fly, and above all no invulnerability to bullets, reveals far greater virtue than Superman - who is only a mere superhero.

The strength of a theory is not what it allows, but what it prohibits; if you can invent an equally persuasive explanation for any outcome, you have zero knowledge.