areopagitica: back story

areopogitica was the name of one of history's most famous political essays written by john milton. in 1664 many years afte his purported meeting with Galileo in 1638 while galileo was under house arrest.  Milton refers his  meeting with  Galileo in the essay.  The essay was inspired by Isocrates (not socrates)entitled Areopagiticus which seesm to be in masculine form as opposed to what seems to be the feminine form ending with an "a" instead of a "us".  For many years I have tried to figure out the significanc of the "a" versus the "us" so far without succss-- i refuse to seek out the nswer more aggressively (say by calling a Galileo and/or Milton scholar.  That would take the fun away as the search for ansers to th e riddles and pieces of the puzle falling slowly into place is part of the fun.