Catoptromancy

Catoptromancy (from Ancient Greek κάτοπτρον katoptron, "mirror," and μαντεία manteia, "divination"), also known as captromancy or enoptromancy, is divination using a mirror.

Methods
There are many different methods of catoptromancy. Some practitioners use a single mirror, while others use multiple mirrors or even crystal balls. Some people look into the mirror in a dark room, while others prefer to do it in natural light. Some practitioners focus on their own reflection, while others look for visions of other people or events.

There is no one definitive interpretation of the images seen in catoptromancy. Some people believe that they are literal representations of the future, while others believe that they are symbolic or metaphorical. Ultimately, the meaning of the visions is up to the individual practitioner to decide. Catoptromancy continues to be practiced today, although it is not as widespread as it once was. There are a number of websites and books that offer instructions on how to perform catoptromancy, and there are even some practitioners who offer professional readings.

Greece and Rome
Pausanias, an ancient Greek traveler, described the practice as follows:

"Before the Temple of Ceres at Patras, there was a fountain, separated from the temple by a wall, and there was an oracle, very truthful, not for all events, but for the sick only. The sick person let down a mirror, suspended by a thread till its base touched the surface of the water, having first prayed to the goddess and offered incense. Then; looking into the mirror, he saw the presage of death or recovery, according as the face appeared fresh and healthy, or of a ghastly aspect."

In Ancient Rome, the priests who used catoptromancy were called specularii. They would use polished metal mirrors to gaze into the future and seek guidance from the gods. Catoptromancy was also popular in medieval Europe, and was practiced by pagans and Christians alike.

Egypt
The practice of catoptromancy is said to date back to the Ancient Egyptians. They believed that mirrors could be used as portals guiding them into the afterlife, or used as a tool to see into the future. Mirrors have been found inside Egyptian burial tombs, and were used in ceremonial practices attempting to contact the dead. For example, a collection of funerary manuscripts known as the Book of the Dead describes a ritual in which a mirror could be used by the recently deceased to unite with their mortal soul by looking at their own reflection in the afterlife.

China
Catoptromancy was also practiced in ancient China. The Chinese believed that mirrors could be used to see into the soul and to predict the future. They would often use mirrors to perform rituals to cleanse the soul and to improve one's luck. For example, one popular ritual involved gazing into a mirror in a dark room and trying to see the reflection of one's future spouse.

India
Catoptromancy was also practiced in ancient India. The Indians believed that mirrors could be used to see into the past, present, and future. They would often use mirrors to perform rituals to gain knowledge and power. The Indian belief that mirrors could be used to see into the past, present, and future is supported by the fact that mirrors are often mentioned in Hindu mythology. For example, in the Mahabharata, a Hindu epic poem, the hero Yudhishthira uses a mirror to see into the future and learn about his upcoming battle.

Use in early Europe
A French book named La catoptromancie grecque et ses dérivés (which translates in English to "Greek catoptromancy and its derivatives") by Armand Delatte from 1932 details the history of catoptromancy in the context of early European history.

Dellate wrote that, in the Middle Ages, mentions of the divinatory mirror appear, "obscure and also uncertain", in the canon of an Irish council "whose convocation is reported by tradition". Historical criticism shows that the collection of these texts cannot go back further than the beginning of the 6th[-][sic]11th century, although certain canons can claim to a more remote antiquity. Here is an example: "I translate literally: 'the Christian, it is said, who believes that there is a witch (lamia or striga) in a mirror, will be anathema, anyone who launches this insult against a person; and he cannot be received into the church before having personally retracted the accusation he has made and thus having done penance with all desirable zeal'. The absence of connection, in the first sentence, between the two relative clauses, as well as the mention of a single measure of reparation and penance, which consists of the retraction of an insult, clearly shows, despite the clumsiness of the editorial, that we cannot dissociate the two faults referred to in this canon: it is the same person who claims to see a witch in a mirror and who, in relation to this first error (as shown by the words this insult), launches against others an accusation of witchcraft. To express our thoughts clearly, sin consists, according to us, of trying to recognize a witch with the help of a magic mirror. Certain modern superstitions and customs can be cited in support of this interpretation. In Thuringia, in Scotland and in the country of Cornwall, we encountered, not long ago, diviners who had the power to make witches and evil people appear, either in an ordinary mirror or in a mirror specially consecrated by magical rites, as well as the author of a theft or any other secret thing. Frazer reports, according to Miss Gordon Cumming, that a family of Nairn in Scotland possessed in the last century 'a crystal ball which, immersed in a bucket of water, becomes a magic mirror reflecting the face of the evil neighbor who bewitched the cattle'. Here we encounter for the first time an example of those combinations of lecanomancy with crystallomancy or catoptromancy to which I alluded previously. The text of the Irish canon therefore seems to me to target a particular use of divination by the mirror, one of those which was considered more dangerous by the Church of the first centuries, because it favored belief in magic."

In popular culture

 * "Snow White" (Magic Mirror) by the Brothers Grimm
 * War and Peace by Leo Tolstoy
 * Mordant's Need by Stephen R. Donaldson