Prominent Egyptian writer Youssef Zeidan on Tuesday posted a letter on his Facebook page correcting a speech recently delivered by President Mohamed Morsi in Pakistan, which the writer described as having been "riddled with errors."

On Monday, President Morsi spoke at Pakistan's National University of Science and Technology, which presented him with an honorary doctorate in philosophy.

According to Zeidan, Morsi's subsequent address – delivered before numerous Pakistani scientists – contained "grave" factual errors.

Zeidan, an expert in Arabic heritage and medical history, criticised Morsi's allusions to the scientific achievements of Muslim innovators during the Islamic Caliphate.

While Morsi cited Abu Rayhan Al-Biruni (973–1048) as the discoverer of pulmonary circulation, for example, Zeidan correctly attributed the discovery to Ibn Al-Nafis, an Arab physician who lived in the 13th century.

"Al-Biruni didn't discover pulmonary circulation, nor had he ever heard of it," Zeidan commented, adding that Al-Biruni had made no contribution to the field of philosophy, as Morsi had also claimed in his speech.

Zeidan also corrected Morsi's pronunciation of Al-Biruni's name.

The Egyptian president had also told his audience that Iraqi-born polymath Ibn Al-Haytham had introduced the world to, among other things, modern anatomy.

Yet Ibn Al-Haytham did not practice the science of medicine or anatomy, asserted Zeidan, who went on to call Morsi out on another mistake: "Mr. President, Gabber Ibn Hayyan [an 8th-century scholar] did not found the science of chemistry as you maintained; chemistry was known centuries before him by the Greeks, Alexandrians and Muslim Arabs."

"Ibn Khaldun, Mr. President, did not 'define sociology' as you said in your speech... which was founded by Auguste Comte and Émile Durkheim and others," Zeidan continued, adding that Ibn Khaldun was only regarded as having provided an early introduction to the field of sociology.

Zeidan concluded by asserting that his only reason for pointing out Morsi's "faults" was his keenness to preserve Egypt's stature and reputation.