I found this interesting.
Example 1.
4 men all strangers are working on a track. Unbeknownst to them a train is barelling down at them and they do not seem to notice. Beside you is a lever that will switch the train onto another track where one worker also a stranger will surely be killed. Do you pull the lever assuring the death of one, or do nothing and assure the death of four?
Example 2.
MASH fans will remember this scenario. You and several villagers are hiding in some dark woods, while the invading army is searching the woods trying to find and kill anybody still alive. Your baby has a cold, can't seem to keep quiet. Cover the babies mouth and you might smother the child. Do nothing and you and everybody including your child will be found and most assuredly killed. What do you do?
However you answer the above consider this. What causes the fight in your brain between logic and empathy. Is it taught to us or is it imprinted into our brain. Did the rules given to us at Mount Sinai factor into it, or simply the thousands of years of trying to make a society work ingrain it in us?