Bonhoeffer on Chastity

Dietrich Bonhoeffer (1906-1945) was a German Lutheran pastor, theologian and activist in the German Resistance movement against Nazism.  His involvement in assassination plots against Adolf Hitler resulted in his imprisonment in 1943 and hanging two years later, just before the end of World War II.  

I like Bonhoeffer's view on chastity, from his book Letters and Papers from Prison:

"The essence of chastity is not the suppression of lust, but the total orientation of one's life towards a goal."