X believes b to be insufficient. Y believes this is be a false observation based on comparison with a.
How can Y argue X must believe c be sufficient?
Oh, that's right. sufficiency is subjective, therefore if Y believes
Um,
why is it that the "more, more, more. there is never enough" argument is always used by those unwilling to try the first "more" ? "here, make do with less."
stuff it all.