Anger ventilated often hurries towards forgiveness; anger concealed often hardens into revenge.
— Edward George BulwerLytton

Self-pity in its early stages is as snug as a feather mattress. Only when it hardens does it become uncomfortable.
Maya Angelou hardens quote

Human beings, by change, renew, rejuvenate ourselves; otherwise we harden.
— Johann Wolfgang von Goethe

All in all, punishment hardens and renders people more insensible; it concentrates; it increases the feeling of estrangement; it strengthens the power of resistance.
— Friedrich Nietzsche

Have a heart that never hardens, and a temper that never tires, and a touch that never hurts.
— hardens quotation by Charles Dickens