"We have to pass through the Slough of Despond, and the sooner we are through, the better."
-Swami Vivekanada
https://www.holybooks.com/wp-content/uploads/SWAMI-VIVEKANANDA-COMPLETE-WORKS-Vol-1.pdf (page 162)
"Do not allow yourself to fall into the “Slough of Despond,” and wallow in the mud of “nothingness,” and to see no reality except in the person of some forceful teacher who takes the place of the Absolute in your mind."
-William Walker Atkinson writing as "Yogi Ramacharaka"
http://www.yogebooks.com/english/atkinson/2014serieslessons.pdf (page 1077)
>Slough of Despond
The Slough of Despond is a fictional, deep bog in John Bunyan's allegory The Pilgrim's Progress, into which the protagonist Christian sinks under the weight of his sins and his sense of guilt for them.
https://en.wikipedia.org/wiki/Slough_of_Despond
>The Pilgrim's Progress
http://www.bunyanministries.org/books/pp_full_text.pdf
All my favorite philosophers have read John Bunyan!