On his release a year later, as he was interdicted from teaching, literature became his only resource.
None of the clergy were to leave the realm, nor were the king's tenants-in-chief and ministers to be excommunicated or their lands interdicted without the royal permission.
He was now interdicted from preaching even in his own convent and again summoned to Rome.
He soon became popular as a lecturer; but the peculiarities of his teaching almost immediately aroused a violent opposition on the part of the university authorities; and before the end of the year he was interdicted from lecturing on the ground of his alleged pietism.
It was synodically condemned along with Hobbes's Leviathan and other books as early as April 1671, and was consequently interdicted by the states-general of Holland in 1674; before long it was also placed on the Index by the Catholic authorities.