Not all things that are said to be good are good, and not all things that are said to be bad are bad.
Most things, after all, are rarely what they claim to be.
To bring us to the point at hand, Mann’s-Eden was neither an eden nor was it Mann’s (observe the use of the proper noun here). He, Mann, had merely claimed it to be so, and man, in time, came to believe Mann … until it was the inarguable truth.