Who lived in the second century? If the first century was Adam and Eve then the second century was Cain Abel and Seth. But they didn't leave any records. How then can Theosophy be traced back to the second century if there was no records? Paul
The second and third century Theosophy traces back to is referring to the time frame of the early Christian Church and neoplatonism. That is more like 200 C.E.
Note:
Some older sources may use AD not CE. (Common Era) i.e. AD = CE.
likewise BCE = Before Common Era so BCE = BC.
I do not think I've seen BC or AD used for quite a while.