Purushamedha (or Naramedha) is a Śrauta ritual of human sacrifice. The Vajasaneyi Samhita-Sataphana Brahmana-Katyayana Srauta Sutra sequence of Shukla Yajur Veda texts contains the most details. Whether actual human sacrifice was taking place has been debated since Colebrooke brought the issue under attention in 1805. He regarded it as a symbolic ritual. Since there is no inscriptural or other record of Purushamedha ever being performed, some scholars suggest it was invented simply to round out sacrificial possibilities. Asko Parpola suggests actual human sacrifices are described in Vedic texts, while the Brahmanas show the practice diminishing. In Shatapatha Brahmana 13.6.2, an ethereal voice intervenes to halt the proceedings. The dhatupatha of Aṣṭādhyāyī by Pāṇini defines the root medha as synergizing the energy to perform something fruitful. Historical development During the Vedic period Scholars doubt the Purushamedha was ever performed. However, according to Jan Houben, the actual occurrence of human sacrifice would be difficult to prove, since the relevant pieces of evidence would be small in number. Rise of Sramanic religions According to Jan Houben, the Later Vedic period was followed by a period of embarrassment about violence in rituals. This period corresponds to the rise of Sramanic religions such as Buddhism and Jainism, both of which place emphasis on nonviolence (ahimsa). This period also corresponds to the composition of the Shatapatha Brahmana, which states that the victims of a Purushamedha are supposed to be released, and the composition of the Chandogya Upanishad, which lists nonviolence as a virtue. Mimamsa movement According to Jan Houben, the Sramanic period was followed by another period where Vedic ritualists tried to defend their actions against Buddhist and Jain criticism. This period corresponds to the rise of the Mīmāṃsā school of philosophy, which claimed that the Vedas were the sole authority regarding matters of dharma. Medieval period By the 10th century, the Purushamedha was included in lists of Kali-varjyas, or actions which were prohibited for the Kali Yuga. This suggests that human sacrifice had become obsolete by the time the texts were composed. However, it also suggests that the Purushamedha may have in some cases consummated with the actual sacrificing of a human. That is, the existence of inclusion of the prohibition in the list of Kali-varjyas demonstrates that at least one author seriously feared the possibility that a ritual practitioner might take the description of the ritual as a moral license to perform the rite