Lingchi (ling2chi2; ), translated variously as the slow process, the lingering death, or slow slicing, and also known as death by a thousand cuts, was a form of torture and execution used in China from roughly 900 CE up until the practice ended around the early 1900s. It was also used in Vietnam and Korea. In this form of execution, a knife was used to methodically remove portions of the body over an extended period of time, eventually resulting in death. Lingchi was reserved for crimes viewed as especially heinous, such as treason. Even after the practice was outlawed, the concept itself has still appeared across many types of media. The term lingchi first appeared in a line in Chapter 28 of the third-century BCE philosophical text Xunzi. The line originally described the difficulty in travelling in a horse-drawn carriage on mountainous terrain. Later on, it was used to describe the prolonging of a person's agony when the person is being killed. An alternative theory suggests that the term originated from the Khitan language, as the penal meaning of the word emerged during the Khitan Liao dynasty. The process involved tying the condemned prisoner to a wooden frame, usually in a public place. The flesh was then cut from the body in multiple slices in a process that was not specified in detail in Chinese law, and therefore most likely varied. The punishment worked on three levels: as a form of public humiliation, as a slow and lingering death, and as a punishment after death. According to the Confucian principle of filial piety, to alter one's body or to cut the body are considered unfilial practices. Lingchi therefore contravenes the demands of filial piety. In addition, to be cut to pieces meant that the body of the victim would not be "whole" in spiritual life after death. This method of execution became a fixture in the image of China among some Westerners. Lingchi could be used for the torture and execution of a person, or applied as an act of humiliation after death.