“Not every change is an improvement but every improvement is a change; you can't do anything BETTER unless you can manage to do it DIFFERENTLY, you've got to let yourself do better than other people!”

“You couldn't changed history. But you could get it right to start with. Do something differently the FIRST time around.This whole business with seeking Slytherin's secrets... seemed an awful lot like the sort of thing where, years later, you would look back and say, 'And THAT was where it all started to go wrong.'And he would wish desperately for the ability to fall back through time and make a different choice. Wish granted. Now what?”

“Doing worse with more knowledge means you are doing something very wrong.”

“It's a most peculiar psychology—this business of 'Science is based on faith too, so there!' Typically this is said by people who claim that faith is a good thing. Then why do they say 'Science is based on faith too!' in that angry-triumphal tone, rather than as a compliment? And a rather dangerous compliment to give, one would think, from their perspective. If science is based on 'faith', then science is of the same kind as religion—directly comparable. If science is a religion, it is the religion that heals the sick and reveals the secrets of the stars. It would make sense to say, 'The priests of science can blatantly, publicly, verifiably walk on the Moon as a faith-based miracle, and your priests' faith can't do the same.' Are you sure you wish to go there, oh faithist? Perhaps, on further reflection, you would prefer to retract this whole business of 'Science is a religion too!”

“...if you're unhappy whenever other people don't picture you exactly the same way you picture yourself, that's already dooming yourself to always be unhappy. No one ever thinks of us just the same way we think of ourselves.”

“Why does any kind of cynicism appeal to people? Because it seems like a mark of maturity, of sophistication, like you’ve seen everything and know better. Or because putting something down feels like pushing yourself up.”

“Lies propagate, that's what I'm saying. You've got to tell more lies to cover them up, lie about every fact that's connected to the first lie. And if you kept on lying, and you kept on trying to cover it up, sooner or later you'd even have to start lying about the general laws of thought. Like, someone is selling you some kind of alternative medicine that doesn't work, and any double-blind experimental study will confirm that it doesn't work. So if someone wants to go on defending the lie, they've got to get you to disbelieve in the experimental method. Like, the experimental method is just for merely scientific kinds of medicine, not amazing alternative medicine like theirs. Or a good and virtuous person should believe as strongly as they can, no matter what the evidence says. Or truth doesn't exist and there's no such thing as objective reality. A lot of common wisdom like that isn't just mistaken, it's anti-epistemology, it's systematically wrong. Every rule of rationality that tells you how to find the truth, there's someone out there who needs you to believe the opposite. If you once tell a lie, the truth is ever after your enemy; and there's a lot of people out there telling lies.”