What is the conflicts between maximus and commodus that drives the movie ?

Commodus killed Maximus's wife and son, who is seeking for revenge.

Explanation:

Movie Gladiator is partially based on historical story about Marcus Aurelius and his son Commodus who inherited the throne of Roman Empire, which eventually led to its decline. Commodus is shown as an incompetent leader, while general Maximus is according to Aurelius the only one who can preserve the unity of the Empire. Aurelius died and Commodus wanted to remove Maximus as he was afraid that Maximus will inherit the throne. Commodus failed to kill him, but instead ordered his family to be killed. Devastated, Maximus is searching only for one thing - revenge, which he at the end accomplished.

darwinism is survival of the fittest there for social darwinism is the survival of the wealthiest