"the immaterial spirit can be purified and refined by clay"

"It is truly astounding how the incorporeal mind can be defiled and darkened by the body.  Equally astonishing is the fact that the immaterial spirit can be purified and refined by clay."

     John Climacus, Scal. 14, as quoted by Inbar Graiver, Asceticism of the mind, Studies and texts 213 (Toronto:  Pontifical Institute of Medieval Studies, 2018), 45n69, who is clearly quoting the Classics of Western spirituality translation by Luibheid & Russell, p. 169.  Greek:  PG 88, col. 869A.  (I have not yet examined any of this closely.)  Trans. Moore, St. John Climacus, The ladder of divine ascent 14.28 (New York:  Harper & Brothers, [1959]), 144:

It is amazing to see the bodiless mind defiled and darkened by the body, and likewise the immaterial spirit purified and refined through clay.