"I was glad you did not pretend to be a saint and claim to love the world despite everything. That is why I decided that I would be your true friend. I would accept your sorrow. And I would share my joy. If you strayed I would reprimand you. If you made mistakes, I would forgive you. And when you found yourself in trouble, I would be there for you. So that you who learn to hate the world, would come to love it once more."

"Think about it this way: a person picks up a sword when he's trying to protect something. Perhaps it's your life or your social status, maybe a reputation, a loved one, or personal beliefs. The motives may be completely different, but in the end, it's the same desire to protect something."

"[to Komamura] Don't make me laugh. Aizen-sama has given me something far more powerful than a bankai."

"It's one of the basics... So I will teach you. A shinigami at the rank of Captain can control the size of his zanpakuto got it? Otherwise everyone'd carry around ginormous swords... just like you. Remember this well. You can't fathom the power of your rival simply from the size of his zanpakuto. You shouldn't give lectures about Shinigami until you understand that."

"You are fighting out of obligation, not out of hatred. You will never reach me like that. Battle without hatred is like a bird without wings. You’ll never defeat anyone like that. You powerless friends are just weights that will break your legs."

"Are you afraid? You don’t want to die, do you? Not just Abarai, if anyone… acts upon the thought of not wanting you to die, you will suddenly begin to fear your impending death, right?"

"[to Szayel Aporro Grantz] Immaculate being... Was it? In this secular existence, perfection is an illusion, regardless of those who utter the contrary. This is the reality. Common man seeks it out, they strive to achieve it, as if it were some tangible thing... But... The fact of the matter is, perfection is a hollow shell. It is devoid of any substance. I spit on perfection. Perfection, after all, implies you've reached the summit. No trial and error, no ability to conceptualize. An omniscient being would have no need for such superfluous things... Am I making myself clear? For people who dabble in the sciences, such as ourselves, perfection would make us obsolete. Many magnificent things have been, and will continue to come into existence... And yet every last one of them will fall short of perfection's finish. Our function as men of science relies on their many shortcomings. Then, and only then, can we apply the fruits of our labor. To put it simply... As soon as you began spouting that nonsense about being an immaculate being... your fate was sealed. How dare you call yourself a man of science?"