The Battle Between Good and Evil
The two main characters in the magical world, Wizard Howl and the Witch of the Waste, are engaged in a battle which is essentially good versus evil. The theme in this novel also extends to showing that being good or evil is a choice as several times it is wondered whether Howl, who was always on the side of good, has turned towards evil instead. The theme is also that through choosing the right path good will prevail.
Love
The novel is a love story of sorts and love dictates the actions of many of the characters. Howl is said to steal the hearts of young girls and metaphorically he does this. When they fall in love with him he loses interest. Sophie is in love with Howl which he knows and for this reason he believes she will keep Miss Angorian from coming in the castle. Sophie is anxious to show she is not jealous about his feelings for her and so let's her in,both courses of action setting off the trail of events that end in the Witch's demise, but both courses of action caused by love. The relationships of Michael and Lettie, and also Fanny and her new husband, also play into the theme of love.
Magic
Magic is one of the main themes of the book. Magic is seen to be something that is pursued as a career choice rather than something that's comes from within, but there are also those in whom the gift lies unbeknownst to them, and Sophie is one of these people. The book shows that magic is magic and only becomes good magic or black magic according to the intentions of the person practicing it.
Importance of Family
Family is a positive theme throughout the novel and although Sophie stays away from her beloved sisters because she can't bear for them to know she has been turned into a crone, they in fact already know and are doing everything they can in order to protect her. She in turn is trying to protect them from the broken hearts she knows Howl will cause them. Similarly Howl will do anything to protect his family from the Witch and does not need magic to do so as his love for them is more powerful than any magic he possesses.
