III. LATIN IMPIETAS
The oldest meaning of pius, pietas seems to have
been “what is acceptable to the gods.” The archaic
formula about just war—puro pioque bello (Livy I,
32)—reflects this way of thinking, which has parallels
in other languages of ancient Italy. Hence piaculum,
piare in sacral language. In the ordinary Latin of re-
publican and imperial times, pius characterizes proper
behavior towards gods, parents and other relatives, and
the Roman state, as well as respect for treaties. “Pius
Aeneas” and “Antoninus Pius” got their nickname from
their behavior towards their respective fathers. Impius,
impietas indicated of course the opposite, and normally
expressed strong disapproval, though there are strange
exceptions in inscriptions which seem to use impius
in the sense of “unhappy.” The influence of eusebes
and asebes accentuated the subjective, personal aspects
rather than the ritualistic connotations of pietas and
impietas. Vergil, more than anybody else, made pius
an attribute of the ideal Roman, and thus rendered
impius an un-Roman qualification. Propaganda in coins
and inscriptions broadcasted pietas. Augustus claimed
pietas as one of his qualities (with virtus, clementia,
iustitia). But impius, impietas never became important
words of Roman political 
ideology 
. They primarily
remained words of the domestic and religious life.
There was never a crime of impietas in Roman law
(notwithstanding some texts to the contrary, such as
Tacitus, Annales 6, 47); religious persecution was based
on other grounds. Latin-speaking Christians had no
difficulty in using
impius and
impietas with the new
meanings which Greek-speaking Christians had
attributed to
asebes and
asebeia: disregard of god,
idolatry, and even heresy.
