Avesta as "Fragments Tahmuras"; and the "Hadokht Nask" "volume of the scriptures" with two fragments of eschatological significance. Only texts preserved in the Avestan language count as scripture and are part of the Avesta. Several other secondary works are nonetheless crucial to Zoroastrian theology and scholarship. The most notable among the Middle Persian texts are the "Dēnkard" ("Acts of Religion"), dating from the ninth century; the "Bundahishn" ("Primordial Creation"), finished in the eleventh or twelfth century, but containing older material; the "Mainog-i-Khirad" ("Spirit of Wisdom"), a religious conference on questions of faith; and the "Book of Arda Viraf", which is especially
Avesta year, the third is recited at the six seasonal feasts, and the fourth at the beginning and end of summer. All material in the "Avesta" that is not already present in one of the other categories falls into a "fragments" category, which – as the name suggests – includes incomplete texts. There are altogether more than 20 fragment collections, many of which have no name (and are then named after their owner/collator) or only a Middle Persian name. The more important of the fragment collections are the "Nirangistan" fragments (18 of which constitute the "Ehrbadistan"); the "Pursishniha" "questions," also known