" I cannot accept that,' said Uriel. 'The destruction of the Emperor's loyal subjects cannot be right.'
'We cannot always do what is right, Uriel. There is often a great gulf in the difference between the way things are and the way we believe they should be. Sometimes we must learn to accept the things we cannot change.'
'No, lord admiral, I believe we must endeavour to change the things we cannot accept. It is by striving against that which is perceived as wrong that makes a great warrior. The primarch himself said that when a warrior makes peace with his fear and stands against it, he becomes a true hero. For if you do not fear a thing, where is the courage in standing against it? "
― Graham McNeill , Warriors of Ultramar (Ultramarines #2)