r war, and incursions into a
neighbouring State without provocation and with the sole purpose of
plunder brought with them no moral blame. To carry the inhabitants of a
conquered country into slavery; to slaughter the whole population of a
besieged town; to destroy over vast tracts every town, village and
house, and to put to death every prisoner, were among the ordinary
incidents of war. These things were done without reproach in the best
periods of Greek and Roman civilisation. In many cases neither age nor
sex was spared![25] In Rome the conquered general was strangled or
starved to death in the Mamertine prison. Tens of thousands of captives
were condemned to perish in gladiatorial shows. Julius Caesar, whose
clemency has been so greatly extolled, 'executed the whole senate of the
Veneti; permitted a massacre of the Usipetes and Tencteri; sold as
slaves 40,000 natives of Genabum; and cut off the right hands of all the
brave men whose only crime was that they held to the last against him
their town of Uxellodunum.'[26] No slaughter in history is more terrible
than that which took place at Jerusalem under the general who was
called 'the delight of the human race,' and when the last spasm of
resistance had ceased, Titus sent Jewish captives, both male and female,
by thousands to the provincial amphitheatres to be devoured by wild
beasts or slaughtered as gladiators.

Yet from a very early period lines were drawn forming a clear though
somewhat arbitrary code of military morals. In Greece a broad
distinction was made between wars with Greek States and with Barbarians,
the latter being regarded as almost outside the pale of moral
consideration. It is a distinction which in reality was not very widely
different from that which Christian nations have in practice continually
made between wars within the borders of Christendom, and wars with
savage or pagan nations. Greek, and perhaps still more Roman, moralists
have written much on the just causes of war. Many of them condemn all
unjust, aggressive, or even unnecessary wars. Some of them insist on the
duty of States always endeavouring by conferences, or even by
arbitration, to avert war, and although these precepts, like the
corresponding precepts of Christian divines, were often violated, they
were certainly not without some influence on affairs. It is probably not
too much to say that in this respect Roman wars do not compare
unfavourably with those of Christian periods.