ommonly
referred to any kind of subject; and in that sense even he who has the
office of governing and directing free men can be called a master. In
the first meaning of mastership man would not have been ruled by man
in the state of innocence; but in the latter sense man would be ruled
over by man in that state.'[3] In _De Regimine Principum_ Aquinas also
accepts what we may call the Augustinian view of slavery. 'But whether
the dominion of man over man is according to the law of nature, or is
permitted or provided by God may be certainly resolved. If we speak of
dominion by means of servile subjection, this was introduced because
of sin. But if we speak of dominion in so far as it relates to the
function of advising and directing, it may in this sense be said to be
natural.'[4]

[Footnote 1: i. 96, 3.]

[Footnote 2: _Ibid._, ad. 1.]

[Footnote 3: i. 96, 4.]

[Footnote 4: _De Reg. Prin._, iii. 9. This is one of the chapters the
authorship of which is disputed.]

St. Thomas was therefore willing to endorse the argument of St.
Augustine that slavery was a result of sin; but he also admits the
justice of Aristotle's reasoning on the subject. In the section of the
_Summa_ where the question is discussed, whether the law of nations is
the same as the natural law, one of the objections to be met is that
'Slavery among men is natural, for some are naturally slaves according
to the philosopher. Now "slavery belongs to the law of nations," as
Isidore states. Therefore the right of nations is a natural right.'[1]
In answer to this objection St. Thomas draws the distinction between
what is natural absolutely, and what is natural _secundum quid_, the
passage which we have quoted in treating of property rights.[2]
He then goes on to apply this distinction to the case of slavery.
'Considered absolutely, the fact that this particular man should be a
slave rather than another man, is based, not on natural reason, but on
some resultant utility, in that it is useful to this man to be ruled
by a wise man, and to the latter to be helped by the former, as the
philosopher states. Wherefore slavery which belongs to the law of
nations is natural in the second way, but not in the first.'[3] It
will be noted from this passage that St. Thomas partly admits, though
not entirely, the opinion of Aristotle. In the _De Regimine
Principum_ he goes much further in the direction of adopting the full
Aristotelian theory: 'Nature decrees that there