Answer:
Six
Explanation:
In the Call of the Wild, first theme is the survival of the fittest. Buck is taken to the wilds of the Klondike, yet he survives since he is better suited to the new environment.
The second theme is power of instinct. Jack London bases his instinct theory on Charles Darwin and Herbert Spencer.
The third theme is loyalty which Buck learns loyalty under the laws of Club and Fang.
The fourth theme is power in which Buck believed before he was kidnapped that he learnt when he was kidnapped and lived among powerful dogs.
The fifth theme is companionship as Buck encounters different companionship in his journey.
The sixth theme is joy of labor as is evident from the idea of socialism.
