The themes involved in The Odyssey are heroism, love, loyalty and the human condition.
Heroism is shown through bravery throughout the book, in many battles.
Love is shown through Helen and Menelaus as well as through Odysseus and Penelope.
Loyalty can be seen in Euryceia and Philoetius.
The human condition is spready throughout, involving these and other themes, such as deception and creativity.