he soon began to regard heresy as a crime similar to treason, and
therefore subject to the same penalty, death. Certain ecclesiastics
of his court with extremely logical minds, and rulers like Pedro II
of Aragon and Frederic II, had reached the same conclusion, even
before he did. Finally, in the fourth year of his pontificate, and
undoubtedly after mature deliberation, he decided to compel the
princes and the podesta to enforce the law condemning heretics to the
stake.

He did his utmost to bring this about. He did not forget, however,
that the Church could not concern herself in sentences of death. In
fact, his law of 1231 decrees that: "Heretics condemned by the Church
are to be handed over to the secular courts to receive due punishment
(_animadversio debita_)."[1] The emperor Frederic II had the same
notion of the distinction between the two powers. His law of 1224
points out carefully that heretics convicted by an ecclesiastical
trial are to be burned in the name of the civil authority:
_auctoritate nostra ignis judicio concremandus_.[2] The imperial law
of 1232 likewise declares that heretics condemned by the Church are
to be brought before a secular tribunal to receive the punishment
they deserve.[3] This explains why Gregory IX did not believe that in
handing over heretics to the secular arm he participated directly or
indirectly in a death sentence.[4] The tribunals of the Inquisition
which he established in no way modified this concept of
ecclesiastical justice. The Papacy, the guardian of orthodoxy for the
universal Church, simply found that the Dominicans and the
Franciscans were more docile instruments than the episcopate for the
suppresion of heresy. But whether the Inquisition was under the
direction of the bishops or the monks, it could have been conducted
on the same lines.

[1] _Decretales_, cap. xv, _De Haereticis_, lib. v, tit. vii.

[2] _Mon. Germ., Leges_, sect. iv, vol. ii, p. 126.

[3] Ibid., p. 196.

[4] Lea writes (op. cit., vol. i, p. 536, note): "Gregory IX had no
scruple in asserting the duty of the Church to shed the blood of
heretics." In a brief of 1234 to the Archbishop of Sens, he says:
_Nec enim decuit Apostolicam Sedem, in oculis suis cum Madianita
coeunte Judaeo, manum suam a sanguine prohibere, ne si secus ageret
non custodire populum Israel ... videretur_. Ripoll, i, 66. This is
certainly a serious charge, but the citation he gives implies
something altogether different.