The Melancholic and Sanguine Temperaments

"One's temperament can never be totally destroyed without destroying the individual. The axiom 'grace does not destroy nature but perfects it' has its most obvious application in the area of temperament."

From Tradition in Action: The Four Temperaments Part I

Image: From the Tradition in Action article, St. Therese of Lisieux is said to have a melancholic temperament.