Do you believe that life begins at conception and that the one day old fetus is just as human as the rest of us? I know many of you do, and I know that you are sincere about that belief, but I wonder just how thoroughly you’ve thought that through. Let’s do a little thought experiment. Consider this scenario:
You work in a fertility clinic. On your way back from lunch one day you notice that the clinic is on fire. You run inside to see if there is anything you can do. To your right is a room where there are five frozen embryos awaiting transplant. To your left you see a two year old girl trapped in a room and screaming for help. There is no time to save both the girl and the embryos. What do you do?
This is a variant of a set of thought experiments commonly known as the Runaway Trolley Car Experiments which were devised in the 1960s to explore ethical dilemmas and how people decide what is and isn’t an ethical action. The general idea was that the subject would be asked to imagine that they were in a difficult situation and had to make one of two actions each of which had negative consequences. They are often referred to as Runaway Trolley Car Experiments because the best known set deals with a runaway trolley car that is barreling down the tracks towards a group of unsuspecting people. The first of that series goes like this:
There is a runaway trolley barreling down the railway tracks. Ahead, on the tracks, there are five people tied up and unable to move. The trolley is headed straight for them. You are standing some distance off in the train yard, next to a lever. If you pull this lever, the trolley will switch to a different set of tracks. Unfortunately, you notice that there is one person on the side track. You have two options: (1) Do nothing, and the trolley kills the five people on the main track. (2) Pull the lever, diverting the trolley onto the side track where it will kill one person. Which is the correct choice? 
In the example above almost everyone agrees that diverting the trolley is the correct action even though it leads to the death of one person. The situations get more difficult from there. What if your only option is to push someone onto the tracks? What if the group of five were convicted murderers? Or just convicted robbers? You can see how it can get very interesting.
So, back to the fertility clinic. You’ve had some time to think about it. What did you decide? Was it a hard choice? This scenario is only a dilemma if you truly believe that an embryo is fully human, and in that case your choice would be as simple as in the trolley car example given above. You act to save the most lives and go for the embryos. However, I suspect that in a real life situation people would be horrified and outraged if someone abandoned the girl for the embryos.
The ethics don’t change even if you swap out the two year old girl for some nameless guy that was just there to fix the plumbing or if you increase the number of embryos from five to fifteen or fifty. I think that almost everyone would agree that the right thing to do is to save the actual human.
For me, this thought experiment indicates that there is something fundamentally different between an embryo and a real, sentient human being. If you are one of those who believes that an embryo is fully human, I would like to hear your thoughts on this experiment.