In 1445 Pope Eugene returned again to the charge, and again issued instructions and commands infallibly committing the Church to the doctrine.

But a greater than Eugene followed, and stamped the idea yet more deeply into the mind of the Church.

On the 7th of December, 1484, Pope Innocent VIII sent forth his bull Summis Desiderantes.

Of all documents ever issued from Rome, imperial or papal, this has doubtless, first and last, cost the greatest shedding of innocent blood.

Yet no document was ever more clearly dictated by conscience.