Salerianus

Poul Anderson's The Stars Are Also Fire (New York, 1995) begins with a quotation attributed to:

"-Salerianus,
"Quaestiones, II, i, 1-16"

Googling "Salerianus Quaestiones," I found only references to the text of The Stars Are Also Fire.

Salerianus begins:

"What did you see, Proserpina,
"When you were down in the dark?"

These lines perfectly blend poetry, mythology and philosophy:

poetry because the form is poetic;
mythology because Proserpina is mythological;
philosophy because the question is about the reality underlying and encompassing life.

Death is:

"The undiscovered country from whose bourn
"No traveler returns..." (see here)

Our ancestors might have believed that Proserpina literally descended and returned but we can easily differentiate the mythological story from the philosophical question.