Abu Isa al-Warraq, full name Abū ʿĪsā Muḥammad ibn Hārūn al-Warrāq (Arabic: أبو عيسى محمد بن هارون الوراق, died 861-2 AD/247 AH), was a 9th-century Arab skeptic scholar and critic of Islam and religion in general.
[1] He was a mentor and friend of scholar Ibn al-Rawandi in whose work The Book of the Emerald he appears.
He argued that if humans are capable of figuring out that, for instance, it is good to be forgiving, then a prophet is unnecessary, and that we should not heed the claims of self-appointed prophets, if what is claimed is found to be contrary to good sense and reason.
Al-Warraq admired the intellect not for its capacity to submit to a god, but rather for its inquisitiveness towards the wonders of science.
That Muhammad could predict certain events does not prove that he was a prophet: he may have been able to guess successfully, but this does not mean that he had real knowledge of the future.