From what you describe it is not aggressive behavior, he is resource guarding. Please DO NOT use Cesar Milan's methods. They are often harsh and often do not fix the problem.
Find a trainer in your area that uses positive reinforcement and can help you with the timing of the reinforcement for good behavior,. People often try to "calm" the dog down by picking them up, giving the treats to distract them or even just talking to them, this will only reinforce the unwanted behavior.
This is really not an issue of aggression, rather training him the correct behavior.
Someday, when scientists discover the center of the Universe....some people will be disappointed it is not them.