Nice points.

C. Dennis McKinsey begins his commentary on polygamy with the words, "Polygamy is widely condemned as repugnant, if not immoral." From there he cites instances of polygamy in the Bible, ranging from the mild (Jacob, two) to the absurd (Solomon, who knows!). The common response to this is to note that God nowhere endorses polygamy; Skeptics may respond that neither is it condemned. The only "condemnation" is implicit and by example. God created but one Eve for Adam. Multiple wives led, for most men who were polygamists, to multiple troubles. Then shouldn't God have said something more direct? Not necessarily. Polygamy counts as one of those acts in the hierarchy of morals that has been reckoned at times to be a "necessary evil" -- not meaning, as McKinsey says, that God changes his mind about what is moral, but that what is moral may be superseded by what is moral on other grounds. To use the classic example, lying is wrong unless you have Jews in your cellar. Then lying becomes a moral imperative.

We therefore need only show that there are circumstances in which polygamy might be a moral imperative, and we can produce these, from a contextually neutral source. Karen Armstrong, certainly no friend of fundamentalism, notes in her biography of Muhammed [190-2] that early Islam allowed polygamy. McKinsey no doubt views polygamy in terms of "pure male chauvinism" and a desire to have many bed partners. In some cases there was no doubt abuse in that direction; Solomon seems to have been a prime example, who paid the price of indiscretion via being drawn into idolatry. However, Armstrong notes social factors in Muhammed's time that mitigated the "evil" of polygamy, and these factors apply just as readily in more ancient Biblical settings:

* Polygamy was Muhammed's solution to the problem of orphans and widows. Men who died for whatever reason left behind sisters, daughters, and other relatives who needed protection. New guardians might not be scrupulous about administering the property of orphans and might even try to keep women unmarried so they could keep the of the deceased husband property. Polygamy allowed an already-married guardian with better interests for the survivors to step in, in an era before there were social, legal and governmental organizations to take up the case. Obviously these conditions applied in the earlier world of the ANE as well.

* Armstrong notes that there was probably a shortage of men in Arabia in Muhammed's era, "which left a surplus of unmarried women who were often badly exploited." Such women in the ANE found themselves compelled to take up a life of prostitution, and less scrupulous persons may resort to female infanticide.

Critics like McKinsey should therefore take some caution before condemning polygamy as "repugnant." The matter is not that simple; the practice would almost certainly be repugnant in our modern nation, because none of the social conditions exist which exert a moral influence making polygamy a "necessary evil." But there is a vast difference between our modern world and the ancient Near East.

http://www.tektonics.org/lp/polygamy.html