So this is what we say. The Cause of all is above all and is not inexistent, lifeless, speechless, mindless. It is not a material body, and hence has neither shape nor form, quality, quantity, or weight. It is not in any place and can neither be seen nor be touched. It is neither perceived nor is it perceptible. It suffers neither disorder nor disturbance and is overwhelmed by no earthly passion. It is not powerless and subject to the disturbances cause by sense perception. It endures no deprivation of light. It passes through no change, decay, division, loss, no ebb and flow, nothing of which the sense may be aware. None of all this can either be identified with it nor attributed to it.
Again, as we climb higher we say this. It is not soul or mind, nor does it possess imagination, conviction, speech, or understanding. Nor is it speech per se, understanding per se. it cannot be spoken of and it cannot be grasped by understanding. It is not number or order, greatness or smallness, equality or inequality, similarity or dissimilarity. It is not immovable, moving or at rest. It has no power, it is not power, nor is it light. It does not live nor is it life. It is not a substance, nor is it eternity or time. It cannot be grasped by the understanding since it is neither one nor oneness, divinity nor goodness. Nor is it a spirit, in the sense in which we understand that term. It is not sonship or fatherhood and it is nothing known to us or to any other being. It falls neither within the predicate of nonbeing nor of being. Existing beings do not know it as it actually is and it does not know them as they are. There is no speaking of it, nor name nor knowledge of it. Darkness and light, error and truth—it is none of these. It is beyond assertion and denial. We make assertions and denials of what is next to it, but never of it, for it is both beyond every assertion, being the perfect and unique cause of all things, and, by virtue its preeminently simple and absolute nature, free of every limitation, beyond every limitation; it is also beyond every denial.
St. Denys the Areopagite 6th-century Christian monk