Answer: allegory
Explanation:
Since Paula learned that in some works of literature, the element in the story has a literal and a symbolic meaning, the literary device that Paula learned about is allegory.
Allegory, is used in passing out a particular message that wasn't set forth in a text or story. Allegory, sometimes uses parables, and fables, to convey a message. A book which is an example of allegory is tge Animal Farm.
Universal truth is something that can't be proven as factual, but is commonly accepted as truth any way.
There is not discernible difference between them.
The author Mary Shelley use the word chimerical in that line because she said that the powers of Cornelius Agrippa were improbable and because she wanted to say this in a fancy way.
Hope this Helps :)
BTW, Mary Shelley is the author of Frankenstein <span />