Porphyry is writing close to the demise of the cult, and Robert Turcan has challenged the idea that Porphyry's statements about Mithraism are accurate. His case is that far from representing what Mithraists believed, they are merely representations by the Neoplatonists of what it suited them in the late 4th century to read into the mysteries. However, Merkelbach and Beck believe that Porphyry’s work "is in fact thoroughly coloured with the doctrines of the Mysteries". Beck holds that classical scholars have neglected Porphyry’s evidence and have taken an unnecessarily skeptical view of Porphyry. According to Beck, Porphyry's "De antro" is the only clear text from antiquity which tells us about the intent of the Mithraic Mysteries and how that intent was realized. David Ulansey finds it important that Porphyry "confirms ... that astral conceptions played an important role in Mithraism."