For no apparent as of yet reason, I was reading a little of St. John of the Cross of purgatory this morning:
Thirdly, we can learn here incidentally in what manner souls are afflicted in purgatory. For the fire would have no power over them, even though they came into contact with it, if they had no imperfections for which to suffers. These are the material upon which the fire of purgatory seizes; when that material is consumed there is naught else that can burn. So here, when the imperfections are consumed, the affliction of the soul ceases and its fruition remains.
The fourth thing that we shall learn here is the manner wherein the soul, as it becomes purged and purified by means of this fire of love, becomes ever more enkindled in love, just as the wood grows hotter in proportion as it becomes the better prepared by the fire. This enkindling of love, however, is not always felt by the soul, but only at times when contemplation assails it less vehemently, for then it has occasion to see, and even to enjoy, the work which is being wrought in it, and which is then revealed to it. For it seems that the worker takes his hand from the work, and draws the iron out of the furnace, in order that something of the work which is being done may be seen; and then there is occasion for the soul to observe in itself the good which it saw not while the work was going on. In the same way, when the flame ceases to attack the wood, it is possible to see how much of it has been enkindled. (Dark Night of the Soul 2.10.5-6)