Tuesday, May 02, 2006


Thanks to Sarah and Glyn to this link to the BBC Magazine, which presents a number of well-known philosophical thought experiments (Thomson's violinist, and the Trolley Problem - which we used for interviews last year, but I guess won't be much good any more!)

Some of the comments almost made me tear my hair out. I'll just mention two:

Thomson's violinist is not the same principle as abortion. If you choose to disconnect yourself you are in essence withdrawing treatment, that is refusing to intervene to save the life of someone who would otherwise die. In an abortion you're choosing to deliberately end the life of someone who would otherwise live.

The foetus is obviously supposed to be not independently viable. Therefore if you 'withdraw' your provision, it will die. Just like the violinist. Someone else does point to a difference:

I would like to point out a problem I have with the direct application of the violinist thought experiment, as presented above, to the case of abortion. In the experiment, if the violinist chooses to stay connected, they need have nothing to do with the violinist once the nine months have elapsed. If a woman is pregnant, and chooses to keep the baby, they will have to bring the baby up - with important consequences for her life, that of the baby, and that of those close to her - or give the baby up for adoption - which again is likely to affect her strongly and will certainly affect the baby.

The natural reading of this is the woman faces further burdens of childcare, beyond the initial 9 months of life support. Accepting the premise (rather than argue the baby allows the woman to live a fulfilled life she couldn't otherwise, or somesuch), then there are further costs to the woman, so if disconnecting the violinist is permissible then so, a fortiori, is abortion. Since the argument is supposed to be favourable to abortion, this isn't really a problem. Abortion will actually be allowed in all cases where disconnecting the violinist is, and maybe some others (because of the higher cost).

Personally, I think it's a shame they didn't discuss Taurek, who discusses one or five cases like the Trolley Problem, and argues fairness requires tossing a coin. No one faces anything worse than death - it isn't worse for any of the five that five die (as opposed to that they die). There is no one who suffers a greater harm of five deaths. Tossing a coin, however, gives everyone a 50% chance of survival.

Also, one other point I owe to Parfit, is one might reasonably think it's better to kill the one in case 3 than case 2. In case 2, that death is (in a sense) gratuitous and unnecessary, because it isn't essential to your plan that there's a person on the other line. In case 3, the fat man's death is necessary, and the essential means to save five. If you were the one killed, would you rather your death did the good of directly saving five, or was merely unfortunate?

For some further thoughts/comments, see Crooked Timber. (But try the survey first, before some insights are given away)

While I'm plugging surveys, my friend Rob offers the chance to plot your views on liberty on his handy matrix. (For now, see the comments thread for my thoughts)

And for those not sick of trolleys, a humorous variant here.


  1. Anonymous11:49 pm

    Hi Ben, I was just reading the crooked timber comments and saw your one. I thought, 'Hey, that is a pretty obscure Parfit reference, I probably know this person...'

    I agree entirely about how painful the BBC comments were -- lots of those people seemed to either miss the point totally, or just wanted to 'prove the example wrong', particularly in terms of there having to be 'other options'.

    To my dismay, I thought the first thirty or so posts on the crooked timber discussion were even worse. Less missing the point perhaps, but more ill thought out aggression (and smug superiority) towards the examples. This is particularly disappointing given CT's reputation for critical thinking.

    Oh, and good work on adding the 'Tissues' link. It is my favourite bit of philosophical humour, even if it is rather overdone.

  2. Anonymous2:09 pm

    I'm not sure you are right regarding comparing the abortion of a non-viable foetus to not supporting the violinist. AFAIK all forms of abortion are active, they involve the destruction of the foetus rather than the withdrawal of life giving support. I realise that this is another hair splitting detail, but that is what these examples are about.

    Therefore the violinist example should specify that it would be necessary to actively kill the violinist to detach yourself from him/her (and that the violinist would die anyway even if this were not the case).

  3. Nick,

    I suppose you're right that we think we can unplug the violinist (where that's what we do intentionally), leaving him to die is a foreseen side-effect. When it comes to abortion, it may indeed be we have to kill the foetus to detach it. I'm not sure that should make a difference, but maybe it does.

    I don't really see that as the point the commentator was making - though whatever she was saying didn't seem very clear: "withdrawing treatment, that is refusing to intervene" almost suggests unplugging is an inaction. Perhaps she hadn't understood that you wake up with the violinist already plugged into you. Maybe she just doesn't express herself like a philosopher(!)