In aikido we don't block a punch,we step slightly out of the attack line and control the strike. So when the punch reaches it's target, we are not...there.
In the same mentality, one should avoid fighting as best as possible, and engage only if he has no other choice.
a bit off topic, but why do we need to get out of the way of the attack? in order to reach me, your body has to be in a certain location and range. what if my fist, foot, and/or weapon occupied that space first?