1 Introduction
As noted by Michael Psellus, some ancients thought that daemons could be scared off by a sword. But this notion is not unique to the Chaldaeans (to whom Psellus attributes it), but found in mainstream Greek texts, namely the ancient commentaries on the Odyssey, which also refer to a more general belief in the power of iron (not just swords) to frighten daemons and ghosts.
The Peripatetic philosopher Alexander of Aphrodisias also tells us that, during eclipses, iron and other metal implements are used to create noise, which also repels daemons.
2 Scholium on Odyssey 10.323
Why did Circe fear the sword of Odysseus even though she is a goddess? We say that the poet was in the habit of referring to those daemons who live for a long time, but yet are subject to death, as gods. Or Circe naturally* feared the sword, as certain daemons also fear certain other materials; as Dionysius says in the Lithika,† “By nature, the crystal and the sacred jasper are hostile to Empusas and other apparitions (eidōla).”
Notes
* Physikōs. But the more appropriate translation may be not “physically” but “magically”.
† The lines are found in the Survey of the Earth of Dionysius; the scholiast is either misattributing the line to the poem Lithika (On Stones), or Dionysius repeated it in the other poem.
3 Scholium on Odyssey 11.48
There is a common conception among humanity that the dead and daemons fear iron.
4 Alexander of Aphrodisias, Problems 2.46
(During eclipses of the luminaries Sun and Moon,) all people shake bronze and iron (objects) in order to drive away demons, because at that moment, the luminaries are not sending down their beneficent emanations, which keep back evil (phauloi) daemons.
SARTRIX 