Syncretism / Eclecticism: Syncretism is never an affair of substance: it is an assembling of heterogeneous elements into a false unity, that is to say, into a unity without real synthesis; eclecticism on the other hand is natural wherever different doctrines exist side by side, as is proved by the integration of Platonism   or Aristotelianism with Christianity. The important thing in any case of the kind is that the original perspective should remain faithful to itself and should only accept alien concepts in so far as they corroborate its faithfulness by helping to illuminate the fundamental intentions of its own perspective.
The Christians had no reason at all for refusing to be inspired by Greek wisdom since it was at hand, and in the same way the Moslems could not help making use to a certain extent in their mystical doctrine of Neoplatonic concepts as soon as they became aware of them; but it would be a serious mistake to speak of syncretism in these cases, on the false assumption of an analogy between them and artificial doctrines such as those of the modern Theosophical Society. There have never been borrowings between two living religions of essential elements affecting their fundamental structures. [GTUFS: LightAW, The Universality of Monasticism]