If Plotinus rose above the vulgar superstitions of the West, while, at the same time, using their language for the easier expression of his philosophical ideas, there was one more refined superstition of mixed Greek and Oriental origin which he denounced with the most uncompromising vigour. This was Gnosticism, as taught by Valentinus and his school. Towards the close of our last chapter, we gave some account of the theory in question. It was principally as enemies of the world and maligners of its perfection that the Gnostics made themselves offensive to the founder of Neo-Platonism. To him, the antithesis of good and evil was represented, not by the opposition of spirit and Nature, but by the opposition between his ideal principle through all degrees of its perfection, and unformed Matter. Like Plato, he looked on the existing world as a consummate work of art, an embodiment of the archetypal Ideas, a visible presentation of reason. But in the course of his attack on the Gnostics,[518] other points of great interest are raised, showing how profoundly his philosophy differed from theirs, how entirely he takes his stand on the fixed principles of Hellenic thought. Thus he particularly reproaches his opponents for their systematic disparagement of Plato, to whom, after all, they owe whatever is true and valuable in their metaphysics.[519] He ridicules their belief in demoniacal possession, with its wholly gratuitous and clumsy employment of supernatural agencies to account for what can be sufficiently explained by the operation of natural causes.[520] And, more than anything else, he severely censures their detachment of religion from morality. On this last point, some of his remarks are so striking and pertinent that they deserve to be quoted.