well, he lived a somewhat stunted, bachelor life well into his 50s.  But knowing Leisl for many years changed him, so that in his later years he could fall into a kind of companionable relationship that didn't frighten or threaten him.

Also, Dunstan did come to terms, through Blazon's analysis of his psyche, with the figure of Mrs. Dempster in his life, especially with his feelings of guilt about her.  In a somewhat ruthlessly practical twist on the idea of God's plan, Blazon counsels Dunstan to accept that Mrs. Dempster's sanity may have been sacrificed to God for a reason, and not to dwell on it and make it his personal problem.  While Dunstan doesn't always agree with Blazon, his advice is certainly good for his self-examination.

Leisl is the one who pegs Dunstan as "fifth business" -- a cognomen which certainly doesn't always fit him -- and makes Dunstan consider him less the protagonist of every drama involving him, but possibly only a supporting character.  This can make a particularly egotistical person depressed, but for Dunstan it can be quite liberating.  Since the weight of the world (or the story) isn't always on his shoulders, it left him free to do what he liked and become more fully who he was. 

I wouldn't say that the growth of Dunstan was dramatic; it was more organic and believable as the maturing, finally, of an old man over many years.  Dunstan began life with fewer weaknesses, perhaps, than other people, but the weaknesses he did have were great and limiting.  That he mitigated these significantly during his lifetime, for his and others' benefit, means that he made real and permanent progress.

The life of Dunstan (originally Dunstable) Ramsay is strongly affected by the childhood incident of rock throwing and his experiences in the war. In his ongoing studies of the saints, he learned about others’ lives more than he lived his own. It took him years to admit that he was not at fault for injuring , which allowed him to appreciate his own positive qualities and forgive his shortcomings. Once his guilt was alleviated, he was also able to live in the here-and-now rather than obsessing about what might have been.

Although it was Boy Staunton who threw the rock that injured Mrs. Dempster, Dunstan continued to feel guilty for not protecting her. After being injured in the war, his long period of recovery gave him time to contemplate his future direction. Through his musings, aided by Diana, he even changed his name. Through his decision to devote himself to studying the lives of the saints, he found an appropriate profession that had elements of a religious calling. However, his studies also placed Dunstan in the position of constantly comparing his behavior to that of the saints. He seemed to have a morbid fascination with martyrdom.

Dunstan’s guilt played out in his efforts to support Mrs. Dempster, apparently placing her needs over his own. Through his interactions with the adult Paul Dempster, Father Blazon, and especially with Leisl, Dunstan learns to assume responsibility for focusing on his own needs. Although he will likely never be guilt-free, he can compartmentalize those feelings and accept the finality of past events.