“There is no peace to be compared with that of the souls in purgatory, save that of the saints in paradise, and this peace is ever augmented by the inflowing of God into these souls, which increases in proportion as the impediments to it are removed. The rust of sin is the impediment, and this the fire continually consumes, so that the soul in this state is continually opening itself to admit the divine communication. As a covered surface can never reflect the sun, not through any defect in that orb, but simply from the resistance offered by the covering, so, if the covering be gradually removed, the surface will by little and little be opened to the sun and will more and more reflect his light.
“So it is with the rust of sin, which is the covering of the soul. In purgatory the flames incessantly consume it, and as it disappears, the soul reflects more and more perfectly the true sun who is God. Its contentment increases as this rust wears away, and the soul is laid bare to the divine ray, and thus one increases and the other decreases until the time is accomplished. The pain never diminishes, although the time does, but as to the will, so united is it to God by pure charity, and so satisfied to be under his divine appointment, that these souls can never say their pains are pains.
“On the other hand, it is true that they suffer torments which no tongue can describe nor any intelligence comprehend, unless it be revealed by such a special grace as that which God has vouchsafed to me, but which I am unable to explain. And this vision which God revealed to me has never departed from my memory. I will describe it as far as I am able, and they whose intellects our Lord will deign to open will understand me.
– Treatise on Purgatory, Chapter 2