The anonymous Cloud of Unknowing teaches that God cannot be grasped by thought but can be reached by love. The contemplative places all creatures beneath a cloud of forgetting and beats on the cloud of unknowing above with a sharp dart of longing love, using a single short word such as God or love. It draws on Dionysius.
The Cloud of Unknowing
A fourteenth-century English treatise teaching that God is reached by love through a cloud of unknowing.
Also: Cloud of Unknowing