While Origen was working out his great system of ecclesiastical dogmatic, his younger contemporary Plotinus, outside the Christian pale, was laying the coping-stone on the edifice of Greek philosophy by a scheme of idealism which must always remain one of the greatest achievements of the human mind.[125] In the history of Mysticism he holds a more undisputed place than Plato; for some of the most characteristic doctrines of Mysticism, which in Plato are only thrown out tentatively, are in Plotinus welded into a compact whole. Among the doctrines which first receive a clear exposition in his writings are, his theory of the Absolute, whom he calls the One, or the Good; and his theory of the Ideas, which differs from Plato's; for Plato represents the mind of the World-Artist as immanent in the Idea of the Good, while Plotinus makes the Ideas immanent in the universal mind; in other words, the real world (which he calls the "intelligible world," the sphere of the Ideas) is in the mind of God. He also, in his doctrine of Vision, attaches an importance to _revelation_ which was new in Greek philosophy. But his psychology is really the centre of his system, and it is here that the Christian Church and Christian Mysticism, in particular, is most indebted to him. The _soul_ is with him the meeting-point of the intelligible and the phenomenal. It is diffused everywhere.[126] Animals and vegetables participate in it;[127] and the earth has a soul which sees and hears.[128] The soul is immaterial and immortal, for it belongs to the world of real existence, and nothing that _is_ can cease to be.[129] The body is in the soul, rather than the soul in the body. The soul creates the body by imposing form on matter, which in itself is No-thing, pure indetermination, and next door to absolute non-existence.[130] Space and time are only forms of our thought. The concepts formed by the soul, by classifying the things of sense, are said to be "Ideas unrolled and separate," that is, they are conceived as separate in space and time, instead of existing all together in eternity. The nature of the soul is triple; it is presented under three forms, which are at the same time the three stages of perfection which it can reach.[131] There is first and lowest the animal and sensual soul, which is closely bound up with the body; then there is the logical, reasoning soul, the distinctively _human_ part; and, lastly, there is the superhuman stage or part, in which a man "thinks himself according to the higher intelligence, with which he has become identified, knowing himself no longer as a man, but as one who has become altogether changed, and has transferred himself into the higher region." The soul is thus "made one with Intelligence without losing herself; so that they two are both one and two." This is exactly Eckhart's doctrine of the _funkelein_, if we identify Plotinus' [Greek: Nous] with Eckhart's "God," as we may fairly do. The soul is