With a view of defending himself, he addressed a letter to the Abbe Castelli, suggesting that the Scriptures were never intended to be a scientific authority, but only a moral guide.

This made matters worse.

He was summoned before the Holy Inquisition, under an accusation of having taught that the earth moves round the sun, a doctrine "utterly contrary to the Scriptures." He was ordered to renounce that heresy, on pain of being imprisoned.

He was directed to desist from teaching and advocating the Copernican theory, and pledge himself that he would neither publish nor defend it for the future.

Knowing well that Truth has no need of martyrs, he assented to the required recantation, and gave the promise demanded.
For sixteen years the Church had rest.