Sentence:  Which "Darkneſs" is a fourth Property of the "Moſaick Matter", and on which "Plotinus" inſiſts pretty copiouſly in this ſecond <WSD>"Ennead</WSD>", and contends we can have no other notion of it, ... 
Meaning of the word marked with <WSD> tags:  One of the six parts of the writings of the Greek-speaking philosopher (Plotinus) ((short=yes) – 270), each containing nine treatises, compiled by his student Porphyry ("c." 234 – "c." 305).