It is a natural inference from the assumption by the Church of the responsibility of indicating in the Index lists the books which are on one ground or another pernicious and which require important corrections, that the further responsibility is assumed of approving by implication the books not thus condemned or not corrected through expurgation. While it is the case that the Church has never admitted this responsibility, the contention is one which has often been raised and which does not appear to have been answered. If the books that are not condemned by the Index are considered as having been approved or even sanctioned by the Church, it would follow that the authority in the Church from which the Indexes emanate could be understood to approve and to sanction those doctrines or assertions from the writers within the fold of the Church which these condemning decrees have failed to proscribe or to expurgate. Such a contention does not appear, however, to be really well founded when we bear in mind the necessary limitations, even in the earlier years of the work of the Index, of the facilities possessed by the examiners in passing upon publications originating in various countries and not always even printed in the common ecclesiastical language. The criticism presents, however, one of the most serious difficulties attending the assumption by the Church of this responsibility for the control of literary productions, even though this control be limited to the writings of members of the Church itself. The Indexes were certainly utilised, and were intended to be utilised, as instruments for the suppression of heresy and for the maintenance of true doctrine as interpreted by the rulers of the Church. The chaplain of Philip II of Spain (Alphonso de Castro) has declared that in his opinion the purification of Spain from heretics was due to the fact that in Spain and in Spain alone the prohibition of heretical literature was effectively enforced. The continued prevalence of heresies in other countries, even in such Catholic States as France, Italy, and South Germany, was, in the opinion of Castro, due to the lack of effectiveness in enforcing the purification of literature.[6] It is the inference of Mendham that the effect referred to by Castro was due not to the simple prohibitions of the Index but to the enforcing of these prohibitions under the thorough-going methods of the Inquisition. Cardinal Pallavicino has assigned the preservation of Italy from the infection of presumed heresy to the activity of the Inquisition and particularly to the work done both by the Inquisition and the Index of the Congregation in suppressing heretical literature. He speaks as if there had been serious risk, in the absence of persistent efforts of this kind, that Italy itself might embrace the Reformation.[7]