Two sailors, peter and Paul, are shipwrecked far out at sea. They spot a plank floating in the distance. It is their sole refuge against drowning, so they swim towards it. Peter reaches the plank first and climbs on. The plank is too small to support both Peter and Paul, so Paul knocks peter off and climbs on the plank himself. Peter proximately drowns. Paul is soon rescued, but is charged with peter's murder when he returns home. Since Paul's survival was at stake, can he claim self-defense?
The scenario above is called The Plank of Carneades. It is a thought experiment proposed by philosopher Carneades around 200 BC. The purpose of the experiment is to examine the relationship between self-defense and murder. It is not one of the most hotly debated philosophical questions, but it is interesting to ponder.
My thoughts on the issue? Paul's argument of self-defense will likely not absolve him of murder. Paul knew Peter would die if he pushed him off the plank, so intent to murder and cause of murder are established. The law has long recognized necessity is not a defense for murder. Paul could not murder Peter to take his lungs because Paul needs a lung transplant in order to survive. Furthermore, peter was not responsible for Paul's life threatening situation. Paul killed Peter because his survival instinct outweighed his conscience. The justice system might be more lenient on Paul because he was under duress, but he still would be convicted for taking an innocent man's life.