Glancing down the centuries we find no time in which Christendom was left wholly devoid of mysteries. "It was probably about the end of the 5th century, just as ancient philosophy was dying out in the Schools of Athens, that the speculative philosophy of neo-Platonism made a definite lodgment in Christian thought through the literary forgeries of the Pseudo-Dionysius. The doctrines of Christianity were by that time so firmly established that the Church could look upon a symbolical or mystical interpretation of them without anxiety. The author of the _Theologica Mystica_ and the other works ascribed to the Areopagite proceeds, therefore, to develop the doctrines of Proclus with very little modification into a system of esoteric Christianity. God is the nameless and supra-essential One, elevated above goodness itself. Hence 'negative theology,' which ascends from the creature to God by dropping one after another every determinate predicate, leads us nearest to the truth. The return to God is the consummation of all things and the goal indicated by Christian teaching. The same doctrines were preached with more of churchly fervour by Maximus the Confessor (580-622). Maximus represents almost the last speculative activity of the Greek Church, but the influence of the Pseudo-Dionysian writing was transmitted to the West in the ninth century by Erigena, in whose speculative spirit both the scholasticism and the mysticism of the Middle Ages have their rise. Erigena translated Dionysius into Latin along with the commentaries of Maximus, and his system is essentially based upon theirs. The negative theology is adopted, and God is stated to be predicateless Being, above all categories, and therefore not improperly called Nothing [_query_, No-Thing]. Out of this Nothing or incomprehensible essence the world of ideas or primordial causes is eternally created. This is the Word or Son of God, in whom all things exist, so far as they have substantial existence. All existence is a theophany, and as God is the beginning of all things, so also is He the end. Erigena teaches the restitution of all things under the form of the Dionysian _adunatio_ or _deificatio_. These are the permanent outlines of what may be called the philosophy of mysticism in Christian times, and it is remarkable with how little variation they are repeated from age to age."[153]