To Sir Phillip, With Love is a historical romance novel written by Julia Quinn and is the fifth in her Bridgerton Series. The book was published by Avon in 2003.
The main theme throughout the book is that of the complications and after-effects of mental illnesses. Phillip is a shell of man after the traumas of living with a mentally ill wife. He has struggled with raising his children as virtually a single father, which puts him at unease when Eloise comes crashing into his life, taking over the position of wife and mother.
As a secondary theme, the book explores the concept of taking new chances on life. Having had a pretty scarred family upbringing, Phillip is untrusting and fearful of starting over again. This is what makes him such a recluse who does not like strangers visiting him. Yet, when Eloise arrives, she brings joy and happiness, and instils a desire in him to take a chance on life again.