The fact that the same author knew other, alternative and logically incompatible etymologies for the same word (mors comes also from amarus, 'bitter', or from the name of the god of war Mars) did not devalue the lesson, since it was the spiritual meaning and not the philological accuracy which stood in the foreground.
The author's knowledge of alternative etymologies for a word (like "mors" coming from "amarus", 'bitter', or the god Mars) didn't diminish the lesson's significance, as it was the spiritual meaning that mattered more than the precise linguistic origins.