72 Law and Morality Abroad (to ca. ad 1550)than did a highwayman to the property of his victims on the road. A key
consequence was that the just side was within its rights to renew the strug-
gle whenever it regained suffi cient strength.
As impressive as medieval just-war doctrine was in terms of coherence, it
cannot be said to have had any great impact on the actual practices of states.
Th en as now, persons holding the reins of power tended to concentrate much
more intensely on their personal or national interests than on the ce re bral
musings of scholars. Nor was the quantity of writing about just wars very
large. For the most part, writers contented themselves with setting out the
basic principles much as has been done here. In terms of actual impact on
everyday medieval life, both natural law and its helpmate the ius gentium
were eclipsed by a third corpus of universal— or at least Western European—
law, known as the ius commune.Th e Ius commune
For all of the prestige that natural law had— even when fortifi ed by the ius
gentium— it should not be thought that the writing on the subject was very
detailed or systematic during the Middle Ages. Th e great age of systematic
exposition of natural law was far in the future— in the seventeenth and eigh-
teenth centuries. In the entire medieval period, there does not appear to
have been a single major treatise devoted to natural law as such (to say noth-
ing of the ius gentium). Writers such as Aquinas rested content with stating
the basic propositions of natural law (i.e., the axioms) and largely leaving it
at that. Natural law might therefore be regarded more as a grand symbol of
medieval universalism rather than an actual application of it to day- to- day
aff airs.
For day- to- day life, a diff erent body of law was devised, to which the bland
label of “ius commune” (or “common law”) came to be applied. In terms of
familiarity to modern audiences, the ius commune is very much the poor
relative of natural law and the ius gentium. Th is is unfortunate, because it
played a greater practical role in medieval legal life than either of its better-
known counterparts.
Although ius commune means “common law,” it must not be confused
with the En glish common law, which was a national law of En gland alone,
that is, a law that was “common” to the whole realm of En gland. In broadly