An embattled senior Vatican official again took to social media on Friday to defend himself from accusations of dishonesty in connection with a book he wrote with another senior churchman on the priesthood and priestly celibacy.

The senior official is the prefect of the Congregation for Divine Worship and the Discipline of the Sacraments, Cardinal Robert Sarah. The other senior churchman is Pope Emeritus Benedict XVI. The title of the book in question is: From the Depths of our Hearts: Priesthood, Celibacy, and the Crisis of the Catholic Church.