From Kingsley again:
Ritter, I think, it is who complains naively enough, that the Alexandrian Neoplatonists had a bad habit, which grew on them more and more as the years rolled on, of mixing up philosophy with theology, and so defiling, or at all events colouring, its pure transparency. There is no denying the imputation, as I shall show at greater length in my next Lecture. But one would have thought, looking back through history, that the Alexandrians were not the only philosophers guilty of this shameful act of syncretism.

From AHD

SYLLABICATION: syn·cre·tism
PRONUNCIATION: sngkr-tzm, sn-
NOUN: 1. Reconciliation or fusion of differing systems of belief, as in philosophy or religion, especially when success is partial or the result is heterogeneous. 2. Linguistics The merging of two or more originally different inflectional forms.
ETYMOLOGY: Greek sunkrtismos, union, from sunkrtizein, to unite (in the manner of the Cretan cities) : sun-, syn- + Krs, Krt-, Cretan.
OTHER FORMS: syn·cretic (-krtk) , syncre·tistic (-kr-tstk) —ADJECTIVE
syncre·tist —NOUN

Apparently AHD doesn't disapprove of it as much as Kingsley