Thirdly, even if we assume that the world is governed by purpose, we need only add that this purpose - or, if there are several, at least one of them - is not especially intent on preventing suffering, whether it is indifferent to suffering or actually rejoices in it.
The problem of suffering is: why is there the suffering we know?
The doctrine of original sin claims that all men sinned in Adam; but whether they did or whether it is merely a fact that all men sin does not basically affect the problem of suffering.