@George,
Thank you. I don't know Latin at all, so this is mostly for fun.
I can't tell if in that construct "meae" modifies "auctoritate", which would be just what I want, "argument from my own authority", or either "argumentum" or the whole preceding phrase, which would be something like "my argument from authority", a different beast entirely. Should it be clear to someone who knows Latin which one is correct?
Again, thank you for your help.