It doesn’t necessarily follow that it’s a highly accurate detector, though. If only a small minority of reasonable people are in this condition, while complete fools are commonly in this condition but their number is still much smaller than this minority of reasonable people, then the above quote would be true and yet your proposed test would be very weak.
A fascinating question would be how strong this test actually is, and how it varies with different subjects.
It doesn’t necessarily follow that it’s a highly accurate detector, though. If only a small minority of reasonable people are in this condition, while complete fools are commonly in this condition but their number is still much smaller than this minority of reasonable people, then the above quote would be true and yet your proposed test would be very weak.
A fascinating question would be how strong this test actually is, and how it varies with different subjects.