Accordingly, the philosophers of Greece, as well as those of the Arabs, Persians, Indians, and every other nation that possesses no revealed Book, do not occupy—regarding matters of the Divine—the same rank as the learned among the People of the Scripture, namely the Jews and Christians; indeed, the latter are more knowledgeable than they in theological affairs. All of these groups, however, stand under the same rule: if a messenger comes to them and they belie him, they are unbelievers; but if they continue to live by the law of a messenger without altering it, they are believers, Muslims, and destined for Paradise. Should they have no revealed law at all and no messenger reaches them, they belong to the era of ignorance (jāhiliyyah), like others who lived in periods between prophets—a matter discussed elsewhere.

Among the philosophers to whom the call of Muḥammad—peace and blessings be upon him—has reached, some outwardly profess Islam, some are Jews, and others Christians. Whoever opposes what the messengers have brought is astray, whatever faction he may belong to, for God sent the messengers with the truth, and sound reason invariably concurs with their message; genuine reason has never contradicted anything they conveyed. This has been treated at length in the book Repelling the Conflict Between Reason and Revelation.

As for the philosophers who present themselves as Muslims, they claim to follow the Messenger. Yet when one scrutinizes their actual statements about God, His angels, His books, His messengers, and the Last Day, it becomes evident to anyone acquainted with the Prophet’s teaching that their discourse is not that of true believers in God and His Messenger. Rather, it contains much that is identical to the utterances of unbelievers and hypocrites.

The various schools of speculative theology (kalām)—despite their innovations and deviations, be they Kharijite, Shiʿite, Muʿtazilite, or Karrāmite—remain closer to the Messenger and to the religion of Islam. However, most