It is a property of friendship that one take delight in a friend's presence, rejoice in his words and deeds, and find in him security against all anxieties; and so it is especially in our sorrows that we hasten to our friends for consolation (ScG 4.22). 

 Thanks for the St Thomas Aquinas ref. I'm now following and was just thinking that his work needs to be on my reading list. Any recommendations to start?