Originally Posted by scarphe
i ma not sure form legal point fo view but i am sure from SD point of view that even pushing is an attack, so the other person is defending himself from an aggressor, he could proabably seriously injure th attacker and still have him charged with assault.
i will repeat the question question what reasoning allows one to attack a person that is not threatening you physically?
From a technical standpoint, you are right. However, realistically, the odds of you be either prosecuted or sued over a push is far less than a punch. I wouldn't recommend either, but, if you're going to do one, I guess your (far) better option would be the push over the punch. This isn't my speciality by any stretch (plus, I practice in a foreign jurisdiction, so there might be some other differences as well), but I can give you a basic statement of general concepts.
Keep in mind that, from a tort (ie. civil law) perspective, assault and battery are two distinct concepts, despite often being used together. A battery is an act of physical aggression (ie. someone were to physically touch you without your permission). On the other hand, an "assault" is merely a realistically perceived threat. In other words, if someone were to get into a fighting stance in front of you, they would be committing an assault but not a battery. However, if they then hit you, they would have performed both. If someone hit you from behind without you having perceived a threat and then ran away, you could likely only seek tortious damages for battery given that there probably was no assault (as odd as that may seem). You can sue someone for damages stemming from a mere assault as well; for example, if somebody pointed a gun at you and this caused you some sort of damage (perhaps you leap to get out of the line of fire and break your leg or maybe you go into nervous shock from the experience), you would potentially have grounds to receive damages for assault.
The same basic concept is transferable to a criminal context. If someone is threatening you in a manner where you realistically perceive that your physical well-being is endangered, you have a right to defend yourself (up to the point where the threat is extinguished and no further; in other words, if someone takes a threatening step towards you, you can defend yourself, but you couldn't then kick them when they were on the ground and the threat was over).
Again, this is not advice but merely an off-hand comment; please do not use or rely on anything posted here in any way.