 The authenticity of the Hippias Major has been in doubt since the middle of the nineteenth century; although many scholars accept it as genuine, there are notable exceptions such as Charles Kahn and Holger Thesleff. The argument against authenticity is based partly on the silence of classical sources about it, and partly on the style. Aristotle’s reference to a dialogue called simply the Hippias is plainly to the Hippias Minor (Metaphysics 1025a6–13). The style is most likely from the fourth century BCE (Plato’s century), but some scholars have argued that its vocabulary places the dialogue too late in the fourth century for Platonic authorship. The argument in favor of authenticity follows the presumption in favor of the ancient canon of Thrasyllus (which is right in most cases) and appeals to the unique and inventive features of the dialogue, which betray more artistry than could be expected from a forger. As with a number of dialogues from the canon, however, the case must be left not proven.