Taoism

Taoism (道教) is a Far Eastern religion and philosophy originating from China, based on being in harmony with the eponymous ("the Way").

In Toaru Majutsu no Index, Taoism is mostly used as a base for certain forms of Magic.

Principles
Part religion and part philosophy, Taoism can be summarized thus: "go with the flow." All problems in life come from going against the natural order of things. Passive virtue is superior to imposing your will, and poverty is better than great wealth.

Everything in the universe is made up from the flow of two equal, opposite, and interpenetrating forces. Yang is solid and masculine, represented by white in the . Yin is the feminine and passive quality, represented by black. From boundless nothingness (wuji) comes the duality of, and from the duality comes "ten thousand things": both light and darkness, good and evil, active and passive qualities are thus contained within the eternal, flowing Tao.

The foundational text of Taoism is the  (also Dao De Jing) written by, the Chinese philosopher seen as its founder. Other important texts include the, which is best known for the story about being a man-dreaming butterfly, or a butterfly-dreaming man.

Being a religion rooted in China, Taoism is deeply infused with Chinese animism and cultural beliefs, and thus shares a number of deities with Chinese folklore and mythology.

Xian
A is a type of being associated with Taoism, said in folklore to be immortal. To be a Xian, one apparently needs to possess a proper skeletal structure, much like people born with the qualities of a Valkyrie or Saint. Some are said to never eat food.

The Shijie-Xian are people who give up their own life to strip away the impurity of a worldly life and become a Xian. They are proper Xians but are apparently sometimes also feared as vampiric monsters. One such Shije-Xian is the Magic God Niang-Niang, who described herself as a heretical Xian who voluntarily took her own life.

Background
Taoism has influenced a number of other fields, such as Feng Shui and Onmyoudou.

Three Stories Arc
Yamisaka Ouma performs the ceremony of extracting Baopuzi from Index to save the girl.

St. Germain Arc
Magic God Niang-Niang is described as a Shijie-Xian.

Necromancer Arc
The Hopping Zombie Spell, which was incorporated into what would become Rosenthal-style Necromancy, is described as a Taoist spell.

Uses of Taoism in the story

 * Baopuzi: A book written by scholar . It discuss topics such as techniques to achieve "Xian".
 * A grimoire from China with a way to become an immortal written inside it. Within the book is the way to learn Rentanjutsu, it's said a person can create a miracle drug to cure any illness or curse using that technique.
 * : An undead creature from Chinese folklore, with some links to Taoism.
 * The Hopping Zombie Spell, likely derived from the Jiangshi, is described as a Taoist spell which was incorporated into what would become Rosenthal-style Necromancy.
 * Shijie-Xian: A type of Xian, who fakes their death with a substitute and abandons their old life in order to obtain a form of immortality.
 * Niang-Niang is described as Shijie-Xian.
 * Xian: A type of immortal found in Taoism and Chinese mythology.
 * Setrua refers to Chinese Xians when describing Brunhild Eiktobel to Kanzaki Kaori, saying how one needs a proper skeletal structure to be one, similar to the qualities for a Valkyrie.