It is well known that married couples exhibit points of likeness and unlikeness, which are visible if they are outward, but not if inward, except to the couple themselves after living together for some time; and others may pick up clues. But it is a waste of time to list either kind to enable them to be recognised, because a list and description of the varieties could fill many pages. It is possible to some extent to deduce and reach conclusions about likeness by studying the unlikenesses, which cause conjugial love to cool off, the subject of the next chapter. Likeness and unlikeness generally speaking arise from the variation induced on innate inclinations by upbringing, company and the adoption of false beliefs.