Hestia as an oath witness: Greek innovation or Indo-European tradition?

In Homer, ἑστία (ion. ἱστίη) “hearth”, “heart Goddess” appears in a fixed formula, where she is invoked by various characters to guarantee the accuracy of an oath statement. The present study analyses the relationship of the fire and hearth, as both sacred symbolic entities and deities, with the oath practices, with the aim of establishing whether this relationship constitutes a Greek innovation or, rather, it can be interpreted as an inherited Indo-European feature. A comparison between the linguistic representations of Greek ἑστία and Indian agni- “fire”, “fire God” is conducted and evidence is provided on the idea that the practice of swearing on the hearth and fire belongs to the Indo-European tradition.