Do No Harm, Do Know Harm. It’s really just two sides of the same coin. If it bleeds you can kill it... Or, save it. As a combat medic/corpsman/tactical medic you are expected to do both. You are an angel and a demon. You are the living incarnation of the dual nature of man, and your ability to do both professionally is what sets you apart from the pack. Our “Duality” iconography was designed with the dual nature of the tactical/combat medical providers in mind.