In Section 18 of Golshan-e Raz, Mahmud Shabestari delineates the Sufi doctrine of the Arc of Descent (qaws-e nuzul) and the Arc of Ascent (qaws-e su'ud). He explains how the soul descends from divine unity into the material plane—passing sequentially through the mineral, vegetative, and animal kingdoms—before beginning its spiritual evolution. The ascent requires the soul to journey back toward the Divine, overcoming earthly attachments, to ultimately realize the state of the Perfect Man (insan-e kamil). This cosmological journey represents the soul's necessary descent into multiplicity and its subsequent evolutionary return to oneness.