First, according to Scripture, "No man shall see God and live" (Exod. xxxiii. 20). Now all discursive exercises of prayer, or even of _active contemplation_, regarded as an end, and not as a preparation for the _passive_, are exercises of life by which we cannot see God, that is, become united to Him. All that is of man, and of his own industry, however noble and elevated it may be, must die. St John tells us that "there was silence in heaven." Heaven represents the depths and centre of the soul, where all must be in silence when the majesty of God appears. All that belongs to our own efforts, or to ourselves in any way, must be destroyed, because nothing is opposed to God but appropriation, and all the malignity of man is in this appropriation, which is the source of his evil; so that the more a soul loses its appropriation, the more it becomes pure. Secondly, in order to unite two things so opposed as the purity of God and the impurity of the creature, the simplicity of God and the multiplicity of the creature, God must operate alone; for this can never be done by the effort of the creature, since two things cannot be united unless there is some relation or resemblance between them, as an impure metal would never unite with one that was pure and refined. What does God do then? He sends before Him His own Wisdom, as fire will be sent upon the earth to consume by its activity all the impurity that is there. Fire consumes all things, and nothing resists its activity. It is the same with Wisdom; it consumes all impurity in the creature, to prepare him for divine union. This impurity, so opposed to union, is appropriation and activity. _Appropriation_, because it is the source of the real impurity which can never be united to essential purity; as the sun's rays may touch the mud but cannot unite with it. _Activity_, because God being in an infinite repose, in order that the soul may be united to Him, it must participate in His repose, without which there can be no union, because of the dissemblance; and to unite two things, they must be in a proportionate rest. It is for this reason that the soul can only attain divine union by the rest of its will; and it can only be united to God when it is in a _central rest_ and in the purity of its creation. To purify the soul God makes use of wisdom as fire is used for the purification of gold. It is certain that gold can only be purified by fire, which gradually consumes all that is earthly and foreign, and separates it from the gold. It is not sufficient that the earth should be changed into gold; it is necessary that the fire should melt and dissolve it, to remove from it all that is earthly; and this gold is put in the fire so many times that it loses its impurity, and all necessity of purification. Then it is fit to be employed in the most excellent workmanship.