The continually changing material conditions of life, with their reaction on the intellectual, emotional, and moral aspects of human affairs, render our societies the most complex and probably the most mobile and unsettled which the world has ever seen.
As the result of this rapidity of change and complexity, there must continually exist a large amount of disco-ordination, and consequently, of suffering.
In a stationary society where generation has succeeded generation for hundreds, or it may be for thousands, of years, with little or no change in the material conditions of life, the desires, institutions, and moral principles of men, their religious, political, domestic, and sexual institutions, have gradually shaped themselves in accordance with these conditions; and a certain harmony, and homogeneity, and tranquillity, pervades the society.
In societies in that rapid state of change in which our modern societies find themselves, where not merely each decade, but each year, and almost day brings new forces and conditions to bear on life, not only is the amount of suffering and social rupture, which all rapid, excessive, and sudden change entails on an organism, inevitable; but, the new conditions, acting at different angles of intensity on the different individual members composing the society, according to their positions and varying intelligence, are producing a society of such marvellous complexity and dissimilarity in the different individual parts, that the intensest rupture and disco-ordination between individuals is inevitable; and sexual ideals and relationships must share in the universal condition.
In a primitive society (if a somewhat prolix illustration may be allowed) where for countless generations the conditions of life had remained absolutely unchanged; where for ages it had been necessary that all males should employ themselves in subduing wild beasts and meeting dangerous foes, polygamy might universally have been a necessity, if the race were to exist and its numbers be kept up; and society, recognising this, polygamy would be an institution universally approved and submitted to, however much suffering it entailed.

If food were scarce, the destruction of superfluous infants and of the aged might also always have been necessary for the good of the individuals themselves as well as of society, and the whole society would acquiesce in it without any moral doubt.

If an eclipse of the sun had once occurred in connection with the appearance of a certain new insect, they mighty universally regard that insect as a god causing it; and ages might pass without anything arising to disprove their belief.

There would be no social or religious problem; and the view of one man would be the view of all men; and all would be more or less in harmony with the established institution and customs.
But, supposing the sudden arrival of strangers armed with superior weapons and knowledge, who should exterminate all wild beasts and render war and the consequent loss of male life a thing of the past; not only would the male be driven to encroach on the female's domain of domestic agriculture and labour generally, but the males, not being so largely destroyed, they would soon equal and surpass in numbers the females; and not only would it then become a moot matter, "a problem," which labours were or were not to be performed by man and which by woman, but very soon, not the woman alone nor the man alone, but both, would be driven to speculate as to the desirability or necessity of polygamy, which, were men as numerous as women, would leave many males without sex companions.

The more intelligent and progressive individuals in the community would almost at once arrive at the conclusion that polygamy was objectionable; the most fearless would seek to carry their theory into action; the most ignorant and unprogressive would determinately stick to the old institutions as inherited from the past, without reason or question; differences of ideal would cause conflict and dissension in all parts of the body social, and suffering would ensue, where all before was fixed and determinate.