There is not one cause, there are many causes, all leading up from the first day of marriage, inevitably, with the unswerving, relentless fatality of Greek Tragedy to the Eighth Year. They are causes which lie deep in the social system of our modern home life; in the little order of things prevailing, at this time, in hundreds of thousands of small households and small flats, inhabited by the middle-classes. It is mainly a middle-class problem, because the rich and the poor are, for reasons which I will show later in this argument, exempt in a large measure from the fatality of the Eighth Year. But all the influences at work among the middle-classes, in this strange age of intellectual disturbance, and of blind gropings forward to new social and moral conditions, have a close hearing upon this seeming mystery. The economic position of this class, its social ambitions, its intellectual adventures, its general education, its code of morality, its religion or lack of religion, its little conventional cults, the pressure of outside influences, thrusting inwards to the hidden life in these little homes, bringing dangerous ideas through the front doors, or through the keyholes, and all the mental and moral vibrations that are “in the air” to-day, especially in the air breathed by the middle-classes, produce--the Eighth Year. Let us start with the first year of marriage so that we may see how the problem works out from the beginning. Here we have, in the first year, a young man and woman who have come together, not through any overmastering force of passion, but as middle-class men and women are mostly brought together, by the accidents of juxtaposition, and by a pleasant sentiment. They met, before marriage, at tennis parties, at suburban dances, at evening At Homes. By the laws of natural selection, aided a little by anxious mothers, this young man and this young woman find out, or think they find out, that they are “suited” to each other. That is to say, the young man thrills in a pleasant way in the presence of the girl, and she sees the timidity in his eyes when she looks at him, and she knows that her laughter, the touch of her hand, the little tricks and graces she has learnt from girl-friends, or from actresses in musical comedy, or from instinct, attract him to her. She leads him on, by absurd little tiffs, artfully arranged, by a pretence of flirtation with other boys, by provocative words, by moments of tenderness changing abruptly to sham indifference, or followed by little shafts of satire which wound his pride, and sting him into desire for her. He pursues her, not knowing that he is pursued, so that they meet half-way. This affair makes him restless, ill at ease. It interrupts his work and his ambitions. Presently it becomes an obsession, and he knows that he has “fallen in love.” He makes his plans accordingly.