The Book of Supreme Truth, by St. John of Rusybroeck (1293-1381)

Behold, such folk, by means of a onefold simplification and a natural tendency, are turned in upon the bareness of their own being; and therefore they think eternal life is and shall be nought else but an enduring state of beatitude, without distinction in order in holiness or in reward. Yea, all such are so deep in error that they say that the Persons shall pass away into the Godhead, and that nought else shall remain in eternity than the essential substance of the Godhead; and that all blessed spirits shall be so simply absorbed with God in the Essential Blessedness that nothing shall remain beside it, neither willing nor working, nor the discerning knowledge of any creature whatsoever. Behold, these men have gone astray into the vacant and blind simplicity of their own being, and they seek for blessedness in bare nature; for they are so simply and so idly united with the bare essence of their souls, and with that wherein God always is, that they have neither zeal, nor cleaving to God, neither from without, nor from within. For in the highest part into which they have entered, they feel nothing but the simplicity of their own proper being, depending upon the Being of God. And the onefold simplicity which they there possess, they take to be God, because they find a natural rest therein. And so they think themselves to be God in their simple ground; for they lack true faith, hope and charity. And, because of the naked emptiness which they feel and possess, they say that they are without knowledge and without love, and are exempt from the virtues. And so they endeavour to live without heeding their conscience, what wickedness soever they commit. And they are careless of the sacraments, and of all virtues, and of all the practices of Holy Church, and believe that they have no need of them: for they fancy in their folly that they have passed beyond all these things, but imperfect men, they say, have need of them. And some men have become so accustomed to and deep-rooted in this simplification that they would know and heed as little of all the works which God has wrought, and all that Scripture teaches, as though not one line had ever been written; for they believe themselves to have found and to possess that for the sake of which all Scriptures have been made, namely, the blind essential rest which they feel. But in fact they have lost God and all the ways which may lead to Him; for they have no more inwardness, nor more devotion, nor holy practices, than a dead beast has. Yet they sometimes approach the sacraments, and at times they quote the Scriptures, that thus they may the better dissimulate and cover themselves; and they like to take some dark saying of Scripture, which they can falsely turn to their own sense, so that they may please other simple men, and may draw them into the false vacancy which they themselves feel. Behold, these folk think themselves wise and subtle beyond any one else, and yet they are the most coarse and crude of all men living; for that which even Pagans and Jews and bad Christians, learned and unlearned, find and understand through their natural reason, these wretched men neither can nor will attain.

- Chapter 4: Of those who practice a false vacancy.