When I read the opening part of the poem about how even though no one has seen God doesn’t mean that he doesn’t exist it did feel something like a preface to make sure he didn’t get in trouble with the Church or make anyone mad. Of course when dealing with blasphemy in the late 1300s to early 1400s the first person that comes to mind is the infamous Thomas Arundel.
I did some digging to try and ascertain when The Legend of Good Women was written and although there is no conclusive answer all the sources seem to agree on a rough timeframe. EChaucer has the Legend of Good Women listed in both 1381-1386 and 1394 while Wikipedia says that “Chaucer wrote many of his major works in a prolific period when he held the job of customs comptroller for London (1374 to 1386). His Parlement of Foules, The Legend of Good Women and Troilus and Criseyde all date from this time. ”
Either way this dates the Legend of Good Women as being written during the reign of Richard II (Henry didn’t usurp him until 1399). However it was most certainly written during Thomas Arundel’s rise to power before being exiled in 1397. Even though he did not wield the power of a Chancellor at that time he was working very hard to fight against John Wycliff and other perceived heretics. I think it’s very possible that even though it wasn’t nearly as dangerous to be a heretic in the late 1300s as it was after Arundel helped Henry IV rise to power, that Chaucer wanted to make sure to included this little disclaimer first and foremost in the poem to ensure that no one got any ideas about burning him at the stake.