I believe authority in the sense of knowing what the meaning of a text is should be passed throw two rules of thumb 1. Is the work of the author understood by the public and 2. Are both the majority of public and the author in agreement on the meaning.
I’ve come to this conclusion because if nobody understands what you’re talking about except you then that reflects on your skill as a writer to get the point across. I think the title of author should be given to of course those who write medical and scientific works but also those who have mastered that ideal of understood work by the majority.
For example. Although Beowulf is seen as a great literary work I personally think it shouldn’t have authority because many people read it and have little ideal of what is going on and what it is interpreting because it is in old English and because the work is simply not complete because some of the manuscript is missing.
I like the point that it’s not so much about the author being right or the reader being right; rather, it’s about finding common ground and taking all contexts–authorial, historical, political, etc.–into account.