pposed to the truth, on which faith is founded; and consequently it
is a species of unbelief.

_I answer that,_ The word heresy as stated in the first objection
denotes a choosing. Now choice as stated above (I-II, Q. 13, A. 3) is
about things directed to the end, the end being presupposed. Now, in
matters of faith, the will assents to some truth, as to its proper
good, as was shown above (Q. 4, A. 3): wherefore that which is the
chief truth, has the character of last end, while those which are
secondary truths, have the character of being directed to the end.

Now, whoever believes, assents to someone's words; so that, in every
form of unbelief, the person to whose words assent is given seems to
hold the chief place and to be the end as it were; while the things by
holding which one assents to that person hold a secondary place.
Consequently he that holds the Christian faith aright, assents, by his
will, to Christ, in those things which truly belong to His doctrine.

Accordingly there are two ways in which a man may deviate from the
rectitude of the Christian faith. First, because he is unwilling to
assent to Christ: and such a man has an evil will, so to say, in
respect of the very end. This belongs to the species of unbelief in
pagans and Jews. Secondly, because, though he intends to assent to
Christ, yet he fails in his choice of those things wherein he assents
to Christ, because he chooses not what Christ really taught, but the
suggestions of his own mind.

Therefore heresy is a species of unbelief, belonging to those who
profess the Christian faith, but corrupt its dogmas.

Reply Obj. 1: Choice regards unbelief in the same way as the will
regards faith, as stated above.

Reply Obj. 2: Vices take their species from their proximate end,
while, from their remote end, they take their genus and cause. Thus
in the case of adultery committed for the sake of theft, there is the
species of adultery taken from its proper end and object; but the
ultimate end shows that the act of adultery is both the result of the
theft, and is included under it, as an effect under its cause, or a
species under its genus, as appears from what we have said about acts
in general (I-II, Q. 18, A. 7). Wherefore, as to the case in point
also, the proximate end of heresy is adherence to one's own false
opinion, and from this it derives its species, while its remote end
reveals its cause, viz. that it arises from pride or covetousness.

Rep