When sparring a younger practitioner for the sake of training, always spar the student at their own level of ability or just slightly more, so as to evoke learning and progress from them. Never beat on younger students and do not allow advanced students to beat on them either.When fighting someone with less training, fight just slightly above their level so as to fine tune and control the level of engagement, at the same time assisting the other person in upgrading their art.
I whole heartedly agree with this statement. In fact, I agree with everything you said SKM. In our system we say fight to your opponents ability. And, if it's a real fight, then fight until there's no fight left in your opponent. This does not mean kill, it just means you are obligated to stop beating them up when they stop attacking you.

ShaolinDan, If you have sparring partners who do not live by this, but instead are there to feed their own egos then I'd suggest moving on. If a student is regularly showing their psycho nature and hurting people on purpose then the instructor or his best student…whoever wears the black hat…should run them out of the school. Violently if needed.

Miyamoto Musashi said in the Book of Five Rings that an injury sustained in martial training should be considered as equal to an injury sustained in battle. I believe he was making the point that martial training is combat training which is serious war training. People should respect this concept because what they are learning can do serious damage to people so it should not be taken lightly.