“Ancient law is hidden in the interstices of procedure” (Sir Henry Sumner Maine). We examine three Indo-European linguistic and cultural analogs form the sphere of legal language, each illustrating a different approach to comparative Indo-European Law. 1) structural: The forms of oath for the three non-servile castes in Hindu law, satyena, vāhānayudhaih, gobījakāñcanaih (Mn.8.113) reflect the hierarchy of Dumézil’s idéologie des trois functions. Parallels for the second and third are noted in Old Norse, Old Irish, and archaic Latin oaths. 2) lexical: Cretan Greek (peuthen), Germanic (*beudan) and Old Irish (ad-boind) agree in attesting forms of the root *bheudh- in the meaning ‘give legal notice (of), announce, proclaim.’ This meaning is inherited and part of the semantics of Indo-European active transitive *bhunédh-ti (*bhunéddhi). 3) institutional: The ‘Pecularly Roman’ opposition of res mancipi/res nec mancipi reflects a traditional hierarchy in the categories of property which is of Common Indo-European origin: large cattle, man, land. Indian law in the sanctions of false witness (Mn. 13.14–16) and Old Iranian law in the classes of contract (Vd. 4.1–4) both make reference to the identical hierarchy of the categories of property, as a traditional ‘yardstick’. By the tenets of the comparative method, these three traditional hierarchies, all equally arbitrarily within their own culture, require the postulation of a common original.