manzia
Catoptromancy
Catoptromancy, from the Greek katoptron "mirror" and manteia "divination", is the practice of gazing into a mirror (or black mirror, obsidian, reflecting water) to receive visions or intuitions. It is a variant of scrying, related to crystallomancy.
Tradition
Catoptromancy was practiced in ancient Greece and in the Roman Empire. Pausanias describes the practice at Patras: a mirror was lowered into a spring, allowed to get wet and then consulted. In the Renaissance, John Dee used an obsidian mirror for his sessions of "angelic scrying". It is also widespread in Russian and European popular traditions of the 19th century.
How to practice it
You fix the surface of the mirror (in dim light, ideally candlelight) in a state of concentrated relaxation. Inner images, apparent shadows, sensations may emerge. Psychology explains many phenomena as pareidolia (the mind attributes shapes to ambiguous stimuli). The practice remains meditative rather than objective.
FAQ
Does it really work?
As a meditative practice it can help enter a state of concentrated relaxation. There is no scientific proof of "objective" visions.
Do I need a special mirror?
In the traditional practice a black mirror is used (obsidian, glass painted black) to reduce direct reflections. A normal mirror in dim light is also fine.
Is it dangerous?
No, it is a harmless practice. You will avoid states of intense fatigue or anxiety, in which pareidolia can become disturbing.