What is the author's style in The Four Loves by C. S. Lewis?

The book is written in first person by C.S. Lewis. It's important to remember that this is a book of inspiration, not a story with a plot and characters. Instead, Lewis gives his thoughts on four kinds of loves and his thoughts on the roles each play in the lives of people—and the roles those loves should play. The fact that Lewis is providing his own thoughts must be considered. He claims that he is not an authority in the field, though he has written several inspirational books.

Lewis offers background and support for many of his opinions. Those range from poets to Biblical references. Again, most poetry and Bible passages are open to interpretation and it's up to the reader to make those connections and evaluations.