the latest investigator of these religious abstractions is at
one with me in believing that they simply mark a developed stage in the
religious bent of the earliest Roman. If the old Romans had the habit of
spiritualising a great variety of material objects, in other words, if
they were in an advanced animistic stage, there seems to be no reason
why they should not have begun to spiritualise mental concepts also (for
which they had words, as for the material objects), even at a very early
period. The whole psychological aspect of such abstractions is most
interesting, but I must pass it over here, merely suggesting that each
of these abstractions was doubtless deified for some particular reason,
under the direction, or with the sanction, of the pontifices.[590]

But we have not as yet reached what is, after all, for our purposes the
most instructive part of the work of the pontifices--I mean the archives
or memoranda (_libri_ or _commentarii_) which they kept, and from which,
indirectly, much of what I have had to say about the _ius divinum_ has
been drawn. It is here that we see the policy of maintaining the _pax
deorum_ carried to its highest point. These books contained a vast
collection of formulae for every kind of process in which the deities
were in any way concerned; here was the complete _pharmacopoeia_ of the
_ius divinum_.[591] We must remember that the pontifex maximus and his
assessors had to be ready at any moment with the correct formula for all
religious acts, whether extraordinary, like the _devotio_ of Decius or
the expiation of some startling "prodigium," or belonging to the
ordinary course of city life, such as prayers in sacrificial ritual,
_vota_ both public and private, charters (_leges_) of newly founded
temples, and so on. The idea that the spoken formula (ultimately, as we
saw, derived from an age of magic) was efficient only if no slip were
made, seems to have gained in strength instead of diminishing, as we
might have expected it to do with advancing civilisation; and the
pontifices not only responded to its importunity, but actually
stimulated it. _Vires acquirit eundo_ are words which apply well in all
ages to the passion for organisation and precision. Though we cannot
prove it, I myself have little doubt that the members of the college, or
some of them, collected and invented formulae simply for the pleasure of
doing it, and that the work became as congenial to them as the
systematisation