O sweet Juliet,
Thy beauty hath made me effeminate
And in my temper soften’d valour’s steel!

– William Shakespeare

Romeo and Juliet, Act 3, Scene 1. Romeo feels shame that Mercutio is dying because he fought Romeo’s fight against Tybalt. Romeo regrets not fighting Tybalt himself. He blames his love for Juliet on softening his valor and making him unmanly. Using a metaphor, he likens his weakened courage to a blunt sword.