faith to which unbelief is
opposed, as shown above (Q. 10, A. 2; Q. 23, A. 6). Therefore schism
is a graver sin than unbelief.

_On the contrary,_ That which results from an addition to something
else surpasses that thing either in good or in evil. Now heresy
results from something being added to schism, for it adds corrupt
doctrine, as Jerome declares in the passage quoted above (A. 1, ad
3). Therefore schism is a less grievous sin than unbelief.

_I answer that,_ The gravity of a sin can be considered in two ways:
first, according to the species of that sin, secondly, according to
its circumstances. And since particular circumstances are infinite in
number, so too they can be varied in an infinite number of ways:
wherefore if one were to ask in general which of two sins is the
graver, the question must be understood to refer to the gravity
derived from the sin's genus. Now the genus or species of a sin is
taken from its object, as shown above (I-II, Q. 72, A. 1; I-II, Q.
73, A. 3). Wherefore the sin which is opposed to the greater good is,
in respect of its genus, more grievous, for instance a sin committed
against God is graver than a sin committed against one's neighbor.

Now it is evident that unbelief is a sin committed against God
Himself, according as He is Himself the First Truth, on which faith
is founded; whereas schism is opposed to ecclesiastical unity, which
is a participated good, and a lesser good than God Himself. Wherefore
it is manifest that the sin of unbelief is generically more grievous
than the sin of schism, although it may happen that a particular
schismatic sins more grievously than a particular unbeliever, either
because his contempt is greater, or because his sin is a source of
greater danger, or for some similar reason.

Reply Obj. 1: It had already been declared to that people by the law
which they had received that there was one God, and that no other God
was to be worshipped by them; and the same had been confirmed among
them by many kinds of signs. Consequently there was no need for those
who sinned against this faith by falling into idolatry, to be
punished in an unwonted manner: it was enough that they should be
punished in the usual way. On the other hand, it was not so well
known among them that Moses was always to be their ruler, and so it
behooved those who rebelled against his authority to be punished in a
miraculous and unwonted manner.

We may also reply by saying that the