 The prioritarian, however, has two impressive hurdles to overcome: how to determine, in health terms, who is “worse off”, and secondly a version of the indirect benefits problem: why should we restrict our focus on health when health resources have knock-on benefits that go far beyond the sphere of health, including becoming a productive member of society. Both issues turn in part on whether health is an intrinsic or an instrumental good (or both). If purely instrumental, then the value of a health improvement—and so an estimate of how worse off a person would be without that improvement—can only be determined by looking at the resulting consequences for the individual and society. Moving in this direction a wide range of considerations—social position, income level, innate talents and good luck—would be determinative, even though they have very little to do with the health benefit itself. If health is only intrinsically valuable, then we would need a direct, unidimensional and comparative metric of health-related disadvantage. This is a formidable challenge since, once again, it would require answers to imponderable questions such as “Is a person who is blind ‘worse off” than a person who is deaf?’