Clement of Alexandria The Instructor Book III The Word prohibits us from doing violence to nature[101] Tertullian On Prayer by naming the sex generally, mingled "daughters" and species together in the genus. Again, while he says that "nature herself,"[133] Tertullian On the Veiling of Virgins , because hair serves for a covering,[30] If Scripture is uncertain, Nature is manifest; and concerning Nature's testimony Scripture cannot be uncertain.[56]