Greg and Compatibilism

Compatibilism is not sufficient as a free-will theory, especially considering this thought experiment: suppose Greg was in the New York City subway system and there was a baby on the tracks with an oncoming train. Further, equidistant from Greg in the opposite direction, was another baby on tracks, with another separate oncoming train. The trains are traveling at identical speeds identical distances away from the respective babies. Greg is the only one who has seen either case, and is the only one who can help either baby, but he cannot help both in time. There are no others around to help, and Greg has mere seconds to act. Greg’s greatest desire is to save both babies. More properly, Greg experiences an equal level of desire to save both babies. In this thought experiment, no prejudices cloud Greg’s mind, and he has no fear for his own safety. Provided Greg was at a vantage point to see and realize at exactly the same time the plight of each baby, which one will he choose to save?

Now, one may object this would never happen in real life, but it’s a thought experiment; what we have described is a logically possible state of affairs. Compatibilism simply isn’t equipped to give us an answer. In the scenario, if compatibilism were true, Greg would be paralyzed, unable to make a decision. Even if compatibilists are willing to accept this outcome, the point would be missed: compatibilism is insufficient to account for decision-making, and thus cannot be itself the decision-maker.

It occurs to me one could just deny such a scenario is possible. That is, he could object that it is impossible that one desire two things equally. However, there appears to be no reason this is so. We would have to see some compelling argument for this. Another escape may be to claim whatever Greg ultimately does in the scenario functions as a choice, and thus this is his choice. That is to say, his greatest desire after all was to remain still, and not to act.

However, it must be pointed out to postulate such is to deny the parameters of the scenario in the first place. Ex hypothesi, the greatest desire is to save the babies, and there were no distinguishing factors for Greg. Hence, to say Greg's greatest desire would be to refrain from action is only true if it is not true that his greatest desire was shared equally between the two babies.

1. Greg's greatest desires are to save both babies.
2. If there are no distinguishing factors between the babies and both cannot be saved, then Greg will refrain from acting.
3. There are no distinguishing factors between the greatest desires.
4. Both cannot be saved (i.e., the desires cannot be fulfilled).
5. Therefore, Greg will refrain from acting (from [1-4]).

What is needed is something like

    6.   If Greg refrains from acting, Greg's greatest desire is to refrain from acting.
    7.   Therefore, Greg's greatest desire is to refrain from acting (from [5-6]).

But all this proves is that (1) and (7) are contradictory. Since (7) is a conclusion, we can simply point out that (6) is rendered implausible, as desire is only a necessary, not sufficient, condition for acting.