“Abiding, then, in charity, and not being able to deviate therefrom by any real defect, they have no will, no desire, nothing but the will of pure love ; they are in that fire of purgatory by the appointment of God, which is all one with pure love ; and they cannot in anything turn aside from it, because, as they can no more merit, so they can no more sin.”  St. Catherine of Genoa, Treatise on Purgatory, Ch. I, final paragraph