The solid foundation of their confidence is the fact that the relationship set up by a comfortable marriage is so intimate and so persuasive of the whole life of the parties to it, that nobody has room in his or her life for more than one such relationship at a time.  What is called a household of three is never really of three except in the sense that every household becomes a household of three when a child is born, and may in the same way become a household of four or fourteen if the union be fertile enough.  Now no doubt the marriage tie means so little to some people that the addition to the household of half a dozen more wives or husbands would be as possible as the addition of half a dozen governesses or tutors or visitors or servants.  A Sultan may have fifty wives as easily as he may have fifty dishes on his table, because in the English sense he has no wives at all; nor have his wives any husband:  in short, he is not what we call a married man.  And there are sultans and sultanas and seraglios existing in England under English forms.  But when you come to the real modern marriage of sentiment, a relation is created which has never to my knowledge been shared by three persons except when all three have been extraordinarily fond of one another.  Take for example the famous case of Nelson and Sir William and Lady Hamilton.  The secret of this household of three was not only that both the husband and Nelson were devoted to Lady Hamilton, but that they were also apparently devoted to one another.  When Hamilton died both Nelson and Emma seem to have been equally heartbroken.  When there is a successful household of one man and two women the same unusual condition is fulfilled:  the two women not only cannot live happily without the man but cannot live happily without each other.  In every other case known to me, either from observation or record, the experiment is a hopeless failure:  one of the two rivals for the really intimate affection of the third inevitably drives out the other.  The driven-out party may accept the situation and remain in the house as a friend to save appearances, or for the sake of the children, or for economic reasons; but such an arrangement can subsist only when the forfeited relation is no longer really valued; and this indifference, like the triple bond of affection which carried Sir William Hamilton through, is so rare as to be practicably negligible in the establishment of a conventional morality of marriage.  Therefore sensible and experienced people always assume that when a declaration of love is made to an already married person, the declaration binds the parties in honor never to see one another again unless they contemplate divorce and remarriage.  And this is a sound convention, even for unconventional people.  Let me illustrate by reference to a fictitious case:  the one imagined in my own play Candida will do as well as another.  Here a young man who has been received as a friend into the house of a clergyman falls in love with the