[A JP classic concerning the article named in the title.]
The theme of Lawrence Foster's piece on the practice of polygamy is that the reasoning used by Mormons to justify the practice was logical though the practice was hard for some to accept. Furthermore, Foster pointed out that the practice was beneficial both to the Mormon community at large and to the women involved in various ways though many saw it as a sacrifice they needed to take to strengthen their religious community. Primary sources from the period support these arguments -- Helen Mar Whitney centered on the sacrifice while Sir Richard Burton spoke about the religious and practical reasons.
Foster discussed an interview with Mormon wife Mrs. Richards that pointed out the sacrifices of polygamy including the end of the ideal of romantic love between a two people. This pointed out the "intense personal commitment and the difficult personal renunciations" involved. Helen Mar Whitney discusses this in her defense of polygamy. She pointed out that both sexes had to sacrifice in polygamy, including the man who had to take care of many wives -- wives, who had the power not to also give aid to the man.
Whitney highlighted the "piety, purity of life" that is the ideal in polygamy and glorified these ideals over those "so narrow minded as to think of no one's comfort and pleasure but their own." This is a reminder that polygamy is not for self-interest, but for the interest of creating a new kingdom of God in the desert. It may require self-sacrifice (Foster noted only 15-20% practiced it), but it has the rewards of salvation.
This idea that polygamy was not meant for one's own pleasure was also noted by Sir Richard Burton. He noted that the Mormons backed up their practice by readings of the scripture and that morality was used to prevent abuse. The key way this was done was to forbid sensuality in marriage unless it was for the purpose of reproduction. This also helped to address the need for more population to increase of number of "God's people," especially with the dearth of men vis-à-vis women (either by population or men away to preach).
Foster gave many reasons why polygamy may be positive to the Mormon community. He noted that it gave status advantages, which Burton noted was a key way women were instructed to accept the practice while Whitney noted it was a status set by piety. There was a great status ("almost cosmic importance" to home and family life that lead to a great value to women, who had the purpose of caring for them. Children was also important because of the need for a work force to settle the land and improve it via irrigation and other ways that took a lot of work. Burton referred to this as an economic motive to have cheap labor via marrying servants (women) that have children to increase the work force.
Foster also noted that the lack of emotional ties of a single partner marriage plus husbands being absent for long periods of time was made up by sisterhood among wives (Burton also noted this development). This also led to women to have more independence since they had to do many "masculine" tasks when the men were absent. They even were given the vote in Utah to show this importance and to strengthen the Mormon vote. The importance of women to make the male happy that Whitney spoke of was therefore quite true.
Men also had a higher responsibility in the system of polygamy. Foster noted that women had a much higher chance to get a divorce in a both socially and legally accepted way, while men had the job of caring for their wives. Burton noted that men with many wives had obligations that led him to in "his interests if not [in] his affections, bind him irrevocably" to caring for his wives, so that polygamy promised security for the women involved. "Brigham, Brigham Young," an anti-Mormon folk song noted the heavy responsibility of the men in polygamous marriages in a satirical way.
Foster's piece therefore validly pointed out that the Mormon practice of polygamy had positive attributes for both sexes and was logical with the needs of the society. The primary sources shows this validity, but also points out the burdens that polygamy contained in order to further religious and social ends. Therefore, the Mormon practice of polygamy can't be examined via a narrow-minded fashion either by supporters or detractors of the practice.