Spoilers...novel and movie excellent. The theme, survival through gumption and a love triangle. At least those are the most noted themes. For me, and I've read the novel and watched the film many times, the main theme is the unlikely partnership of Scarlett and Melanie. Scarlett detests Melanie, Melanie blindly loves Scarlett. Tragedy and circumstance bring them together to battle for survival side by side each providing their unique strengths and without both, neither would survive: Scarletts practical skills and Melanie's social skills work alternately and in tandem to secure the survival of themselves and loved ones.