In a Vatican communiqué, it stated the pontiff decided to delay his trip to La Sapienza University because of the controversies swirling around his visit to open the institution for a new academic year.
"Following the well-noted controversy of recent days ... it was considered appropriate to postpone the event," which had been set for Thursday, a Vatican communique said.
The Italian government has expressed outrage at the protest, saying the pope was entitled to the freedom of speech while Dario Fo, a Noble prize winner and outspoken critic of the Roman Catholic Church, insisted everyone, including the pontiff, has a right to speak.
"I deeply regret Pope Benedict's decision," Italian Prime Minister Romano Prodi said, inviting him to reconsider.
"No voice should be silenced in our country, and all the more so when it comes to the Pope."
Earlier in the week, 67 professors wrote a letter requesting the university to reconsider the invitation sent to the pope given that he was a backward theologian who put religion ahead of science.
Before becoming the pope, Cardinal Joseph Ratzinger quoted an Austrian philosopher and said the Inquisition ruling against Galileo was 'rational and just.'