CORPUS CHRISTI, TX (Catholic Online) - Our thesis and task during our series of articles on Muhammad entitled "The Heart's Witness Against Muhammad," have not been very complex. 

Our thesis was this: An alleged prophet of God, especially one who is presented to us as a perfect exemplar of humanity, al-insan al-kamil, the best of all mankind, khair ul-bashar, the perfect model of conduct, uswa hasana, must at a minimum comply with the natural moral law.  This is a reasonable requirement.

Our task, given this thesis, was then this: to familiarize ourselves with the earliest Islamic sources on the life of Muhammad, accept them uncritically (that is, accepting them as historically-accurate portrayals of the historical Muhammad), and then, compare and contrast the behavior of Muhammad to some well-known, universally held notions of the natural moral law. 

This gives the benefit of the doubt to Islam and its sources.  It could very well be that Muhammad's actions were "whitewashed" by his followers.  For example, why on earth would the earliest of all biographies, the biography of Ibn Hisham, have been lost?  Why do we only have recensions or edited versions of it in the biographies of Ibn Ishaq and at-Tabari?  What parts of Ibn Hisham did not survive?  Was there possibly a "scrubbing" of the earlier biography and its ordered destruction by the Caliphs such as what seems to have happened to a limited extent with regard to the Qur'an?

Also, we must recall that we do not have biographical sources from contemporaries who witnessed Muhammad and rejected him and his message (other than that found in Muslim sources).  We know that many Jews, Christians, and Pagans found Muhammad and his message offensive, unbelievable, and violent.  These historical documents, if they existed, would, in all likelihood, provide us with an even more offensive picture of the alleged prophet of the Arabs that the historical documents the Arabs preserved.

In other words, the Muhammad of the Qur'an, of the ahadith considered by the Muslims as reliable, and the earliest approved biographies or Sira of Muhammad present Muhammad in the most biased, best light.  If these sources cannot justify Muhammad, then the other sources certainly would not justify Muhammad.

As a standard of the natural moral law, we turned to what is generally regarded as a good summary of the natural law and its basic and essential precepts, the Ten Commandments or Decalogue.  These are revealed, but the underlying laws are not revealed.  They existed in full force as a result of the natural moral law before they were handed to Moses.

We passed over the first three commandments--those that deal with man's relationship with God--because they presuppose, to some extent, truths of revelation. 

The question of what may be reliable revelation is a question that must be answered after we accept the carrier or messenger or prophet of that revelation. 

Reason, of course, can also be used as a critical faculty for showing where revelation cannot be authentic because it is unreasonable, since God is both the author of faith and the author of reason.  We have not in any way made an assessment of Muhammad's supposed revelations of Allah and whether they are reasonable.  That is a task for another day.

Revelation acknowledged by Christians as authentic (for example the teachings of Christ in the Gospels) and the teachings defined as de fide by the Church may also be used to criticize the message of an alleged messenger of God.  But to have recourse to this form of analysis we must have already accepted this revelation as authoritative.  Only a Christian can recognize the force of the arguments against the teachings of Muhammad on the basis that Muhammad denies the Trinity, denies the divinity of Christ, and denies Christ's substitutionary and atoning death on the Cross.

But we wanted an argument based upon reason alone, practical reason, moral reason.  We therefore focused on those Commandments that relate to relations among men.  We chose six: you shall not commit adultery, you shall not covet thy neighbor's wife, you shall not murder, you shall not bear false witness, you shall not steal, and you shall not covet thy neighbor's goods.
 
The only commandment we did not treat was the commandment that enjoins us to honor our mother and father.  (Since Muhammad's father predeceased his birth, and since Muhammad's mother died when Muhammad was young, there is no data to which we can turn to assess his behavior toward them.  There is interesting speculation as to whether he thought them--as polytheists and therefore guilty of the unpardonable sin of shirk--damned in hell.  For example, there is a story that ...