In The Keys of the Kingdom Cronin is concerned with two main themes, one of which is a constant concern throughout his life and work, while the other was never to appear again with such fervor. The first is Cronin's concern for children who are ill-treated or neglected. As is often the case in Cronin's novels, children also have great potential intellectually and socially.
His protagonist, Francis Chisolm, is such a child, an orphan, and when he is removed from adverse conditions in which he is being raised, the reader sees Chisolm bloom into a bright youth who is full of unprejudiced compassion, a trait which his early hardships brought to him. Such a theme recurs in Cronin's works, as, for instance, in the character of Mary in Hatter's Castle (1931; see below).
The second theme is theological.
Francis becomes a priest, but from the time he begins...