What Causes Aggressive And Abusive Behaviour In A Person?

Hi.... I am dating a man who, thru lies or other negative actions, creates violent situations which always end up with me getting physically injured. I recently took the last injury from him I will ever take again at him. Here is where I am unable to understand what he always does next....he completely ignores, denies, blocks etc the reason for the final outcome of his rage episodes that result in me getting physically hurt. He starts each episode usually during a conversation dealing with anything serious or where he has done something I feel isn't fair or truthful. He will immediately begin to yell and start to point out my faults. Then he will move towards me yelling, cursing and pointing his finger in my face. I will ask him to stop or move away from me repeatedly...he only presses harder until I become scared, threatened etc that I will feel I have to become physical in order to escape his aggressive behavior. I will tell him I am going to hit or slap him if he wont stop. he will challenge that and I will go thru with my actions. this is when he justifies his dangerous violent actions that always end with me getting seriously hurt. Even as this usually causes me to be unable to move for a few minutes or even be knocked unconscious for a few seconds...he will continue the exact same behavior. I literally have to pretend to go " psycho" on him by screaming uncontrollably or yelling for help or some other abnormal action. Some times he will react to that by choking me or restraining me by force to the point of breaking a bone. The only explanation he ever gives for my injuries is the part where I react and lash at him causing him to respond by causing major pain to me. He seems to erase the beginning of the episodes that last 10 to 15 minutes of his screaming, cursing, putting his finger in my face or popping the top of my head until I feel I have to defend with violence to escape the situation. We could never get past this behavior due to the fact his recollection of things started with me assaulting him for no reason!! How or why is he able to think that way and believe it is true? Help!