Philosophers have puzzled about how to justify our intuitions in these situations, given that in both cases, the choice seems to be between saving five lives at the cost of taking one life. Greene, however, was more concerned to understand why we have the intuitions, so he used functional Magnetic Resonance Imaging, or fMRI, to examine what happens in people’s brains when they make these moral judgments.
哲学家们为如何证明我们在这种情况下的（道德）直觉的正当性而颇费脑筋。因为在两种情况下，我们的选择似乎都是牺牲一条命，拯救五条命。然而格林更想了解的是我们 为何 会有这样的直觉。所以他运用了功能性核磁共振设备（FMRI）来检测人们做出这些道德判断时大脑中发生的情况。