Man's World
Thelma is nearly raped by a man in the parking lot of a bar before Louise stops him, and after he screams that he should have raped Thelma, Louise shoots him dead. Louise was years earlier raped in Texas, and has kept it very private. We later see a trucker issuing lewd gestures at Thelma & Louise while on the road, as if they are meant to respond to his every sexual fantasy on command because he's a man. The theme is that Thelma and Louise, like most women, live in a world saturated by men who get away with taking what they want from women without any penalty. Thus Louise & Thelma begin to issue their own form of justice.
Love
Love is a major theme in this film between Thelma & Louise. The two are best friends, and they become closer over the events of the story as they must continue to rely on one another more deeply than before. And with every obstacle and hard circumstance they have found themselves in, they never let the other down, even to the very end.
Hope
Detective Hal Slocumb is the character in the film that represents hope. Yes, he is in pursuit of the two women for murder, but he uniquely understands their story and the circumstances they find themselves in and does his best to help them. In the end he is denied the chance to speak to Thelma & Louise in order to bring them in safely, and when they plummet off the Grand Canyon's edge he is seen on feet chasing after them in one last fleeting attempt to help them.