ar and strife denote actual aggression on either side, whereas
sedition may be said to denote either actual aggression, or the
preparation for such aggression. Hence a gloss on 2 Cor. 12:20 says
that "seditions are tumults tending to fight," when, to wit, a number
of people make preparations with the intention of fighting. Secondly,
they differ in that war is, properly speaking, carried on against
external foes, being as it were between one people and another,
whereas strife is between one individual and another, or between few
people on one side and few on the other side, while sedition, in its
proper sense, is between mutually dissentient parts of one people, as
when one part of the state rises in tumult against another part.
Wherefore, since sedition is opposed to a special kind of good,
namely the unity and peace of a people, it is a special kind of sin.

Reply Obj. 1: A seditious man is one who incites others to sedition,
and since sedition denotes a kind of discord, it follows that a
seditious man is one who creates discord, not of any kind, but
between the parts of a multitude. And the sin of sedition is not only
in him who sows discord, but also in those who dissent from one
another inordinately.

Reply Obj. 2: Sedition differs from schism in two respects. First,
because schism is opposed to the spiritual unity of the multitude,
viz. ecclesiastical unity, whereas sedition is contrary to the
temporal or secular unity of the multitude, for instance of a city or
kingdom. Secondly, schism does not imply any preparation for a
material fight as sedition does, but only for a spiritual dissent.

Reply Obj. 3: Sedition, like schism, is contained under discord,
since each is a kind of discord, not between individuals, but between
the parts of a multitude.
_______________________

SECOND ARTICLE [II-II, Q. 42, Art. 2]

Whether Sedition Is Always a Mortal Sin?

Objection 1: It would seem that sedition is not always a mortal sin.
For sedition denotes "a tumult tending to fight," according to the
gloss quoted above (A. 1). But fighting is not always a mortal sin,
indeed it is sometimes just and lawful, as stated above (Q. 40, A.
1). Much more, therefore, can sedition be without a mortal sin.

Obj. 2: Further, sedition is a kind of discord, as stated above (A.
1, ad 3). Now discord can be without mortal sin, and sometimes
without any sin at all. Therefore sedition can be also.

Obj. 3: Further, it is praiseworthy to