Kegare is a notion in Buddhism and Shinto and means a dirty, bad, not clean state, such as being unclean, impure etc.
Originally, it simply referred to becoming injured as a modern term 'Kega (怪我) (injury)' was written in Manyo-gana (a form of syllable used in the Manyo-shu or Collection of Myriad Leaves.)
A difference between 'Kegaru' and 'Yogoru' is as follows:
Yogoru is a temporary and shallow impurity that can be removed by acts of cleaning, but 'Kegaru' is a continuous and inner impurity and a type of impurity which seems to be removed by ritual ceremonies such as 'Kiyome,' etc.
Subjective feeling of impurity
Kegare and sin are often collectively called as 'Tsumi Kegare' and while Tsumi is caused by man, Kegare is thought to arise naturally. Upon attachment of Kegare to someone's body, it was believed that Kegare would disturb the order of both the person and the community the person belonged to and generate troubles for both. While Kegare increased even in ordinary daily lives, Kegare was thought to attach to people's body from death, plagues, child birth, period and crimes, and persons with Kegare were prohibited to be involved in ritual ceremonies, conduct Chosan (a visit of a government official to the imperial court) and enter mountains to hunt, char-grill lumbers, etc.
Kegare can be removed by Misogi or Harae (form of Shinto purification.)
Tsumi (sin) is the same as 'Tsutsugami (harm)' and means mental injury or trouble and sadness or sorrow from it.
Ethnic studies in recent years show an idea that 'Kegare (ケガレ)' is '気枯れ,' which is the state in whicht Ke and Hare (noticeably cheerful and formal situations or such places) disappeared, and Ke has to be recovered (remove Kegare, 'Ki o yomeru (気を良める)'=>Kiyomeru (clean)) by holding Hare ceremonies such as a festival.
Refer to the 'Hare and Ke' section for more details.
There are similar notions in other religions or folk beliefs. Refer to the general notions of Kegare on this respect.
Kegare in Japanese myths
Izanagi went through Misogi after he was back from Yominokuni (hades, realm of the dead, the next world.)
This was an act to remove Kegare which had attached to him in Yominokuni, and gave birth to a lot of Kami (god) during the course of Misogi. Mihashira no uzuno miko (three noble children) were among them. Kami was also born from removed Kegare.
The first appearance of Kegare was 'Kegare of death' which was related to the death of Tomomewarawa (servant) appearing in a tradition where Susano directed Ama no fuchigoma Horse to break into Amaterasu's residence.
Shinto and Buddhism
Both Shinto and Buddhism are conscious of Kegare, but the biggest difference between the both is the notion of death, and while Shinto considers death and blood as Kegare, Buddhism does not regard death as Kegare like Shinto does. A Buddhism funeral may be held at a temple, and a Shinto funeral is held at a place other than a shrine which is regarded as the holy precincts. This depends on what the holy thing is, and salt for purification is intended to remove Kegare. This Kegare refers to death itself rather than a dead person. In Buddhism, death represents the Rinne (the wheel of life) world in reincarnation takes place, and there is no concept to deny this. It means trying to escape from such a phenomenon. Buddhism dislikes that Kegare is accumulated in a form of karma, that is based on logic. In other religions, there is some logical basis for all things that are disliked such as Kegare.
Other notions of Kegare (a sense of discomfort) which have been established since ancient times in Japan can be seen in people's ordinary life. Manners in eating meals is one. Such notions are thought to have been ancient shamanism which indigenously existed all over the world, but they, in many ways, have become vague or ambiguous as a result of the spread of religions and people's relocations in the world.
Kami (god) was mythical and venerable for Japanese people (Goryo-shinko (a folk religious belief of avenging spirits.))
People appeased Kami, who inspired a sense of fear in them, by enshrining and worshipping them as holy spirits. The Emperor was believed to be from Amaterasu Omikami (the Sun Goddess) regarded as Kososhin (Imperial ancestor) and a respectful person as well as Kami. Shrines to enshrine such Kami were a temporary place where Kami descended from Iwakura (dwelling place of a god, usually in reference to a large rock) or Kinsokuchi (tabooed land,) and ritual ceremonies were performed, but gradually, Haiden (a hall of worship) was built as a substitute for Kinsokuchi and Honden (a main shrine) was built to let Kami reside there. Such Kami and Kegare are not compatible, and that is why Chozusha (purification trough) is placed at a shrine to remove outside Kegare from visitors.
Syncretization of Shinto with Buddhism exists in many places in Japan and the ideas and concepts of both are somewhat mixed up or confused (Torii (an archway to a Shinto shrine) and construction style at a shrine.)
The same mix-up and confusions also apply in Kegare.
Origin of Kegare
It is thought that the notion of Kegare was imported in Japan during the Heian period. The notion that death, child birth and blood were Kegare originated in Hinduism, and flowed into Buddhism which had arisen in India as well. Particularly, most Buddhism imported to Japan in the Heian period had this thought, and the notion of Kegare spread from Kyoto to all other places in Japan.
From looking down to seeing the unclean
Before that time, there also was a caste system in Japan such as Nuhi system in Yamatai-Koku kingdom and Goshiki no sen (Ryoko, Kanko, Kenin, Kunuhi, Shinuhi) in the Nara period, and was a way of exhibiting disdain (a way of looking down.)
On the other side, after the arrival of the notion of Kegare, discrimination against discriminated people changed, in that they were seen as unclean (to see them Kegare.)
It is represented by the fact that the most typical humble people in the Edo period were called Eta (meaning much Kegare.)
Relation to Shinto
There is a theory that though Kegare was a notion which had been originally brought into Japan with Buddhism as mentioned above, it was gradually syncretized with the concept of Shinto in which the Emperor was seen as holy, and as a result, the discriminated were thought to be Kegare people who were at the opposite end of the Emperor. There were discriminated people called 'Hakucho' (inferior servants) in Korean Peninsula who were engaged in slaughtering cows and horses and leather industry, and in medieval Germany, there were cases in which books were burnt in a slaughterhouse of cows and horses. However, there are objections towards the thought that this type of discrimination is directly connected with Shinto. Close relations between discriminated people and the Emperor were clarified through research by scholars such as Yoshihiko AMINO, etc.
There is a view that the Emperor is an awesome person who has a function of 'Kiyome' (cleaning of unclean things.)
Masao TAKATORI thinks that the notion of 'Kegare' changed because of the notion of uncleanness in Buddhism ("Shinto no seiritsu" (Formation of Shinto.))
General notion of Kegare
A notion corresponding to Kegare or uncleanness exists in many cultures on one nature and level or another. It was an important view for people living before the modern period or in uncivilized areas in which there was no scientific knowledge as we have now. It was thought that upon physical or mental contact to a thing with Kegare, the Kegare was infected. It can be explained to modern people that cleaning one's hands and body aims to wash away viruses, but it did not mean so for ancient people, and rather, the purpose was both to take off visible dirt and remove Kegare. This remains in various religious ceremonies such as purification ceremony, Kanjo (the esoteric Buddhist ritual of pouring water on the top of a monk's head) and being christened. It is believed that a conception of treating sin and Kegare in the same way like 'sin and Kegare' in Shinto was not a special one in ancient periods.
Typical things with Kegare are death, disease, injury, women and all things related to the four mentioned above.
Though they may differ depending on the culture and religion, some concrete examples are egested things, rotten things, blood, body fluid, period, child birth, particular or general animals and foods, all contacts and acts between women and between men and women (very rarely, sexual relations and acts between men and people of the same sex,) people outside own community (people of other prefectures, foreigners and different races,) culture, people of particular blood line or rank (scheduled castes,) particular occupations (entertainment, financial and meat industries) and particular parts of a human body (a left had can not be used for eating, etc.)
These are not necessarily absolute Kegare, and differ in many cases depending on acts (e.g. it is alright to touch a certain animal, but eating it is prohibited, etc.)
The notion of Kegare is recognized not only in folk religions but also in many primary religions. In Judaism, various notions of Kegare have been determined in detail for a long time, and this affected Islam in regard to the food taboo and also have left imprints on many people's life styles even in modern times. A notion of Kegare in Brahmanism was succeeded by modern Hindu and also left imprints on Buddhism.
Opposite concept for 'Kegare' is 'purity' or 'sacredness,' but both Kegare and sacredness are often the subject to be avoided as taboo things and it is only emphasized that both are taboo and it is not always possible to distinguish one from another strictly. Taking Judaism as an example, animal's blood is hated as much as 'unclean living thing' only for eating, but this is because animal's blood is a holy thing which is described as 'blood is life, so it can not be eaten' (Deuteronomy) in Judaism and not because animal's blood is a thing with Kegare.