User blog comment:DancePowderer/Aokiji Vs. Akainu, Part 2/@comment-4904935-20130204185806/@comment-1595565-20130204191807

Aokiji and Akainu represent the two extremes in Marine thought. Aokiji is calm, cool, and collected. He thinks things through. Akainu is hot-headed and rash. He's quick to jump. Sengoku believed that leading the Marines in the new era took rationale, while other people (in my case, Kong) thought that someone who took absolute justice way too seriously should be fleet admiral. And then there's Kizaru. He represents neutrality or balance. He's quick to attack, but at the same time rational about whom he is attacking and why. It has nothing to do with power. After this explanation their powers and the colors associated with them should start to make more sense. So to answer your original question, it is Marine politics with just a touch of philosophy thrown in. Personally, I believe Akainu became fleet admiral because shit would be a lot less interesting if Aokiji or Kizaru got the job.