The dominant theme of the novel concerns the transformations effected by time in a person’s life. Bennett was inspired to write The Old Wives’ Tale by an incident in which he saw an old woman and imagined how different she might have been in her youth: “This woman was once young, slim, perhaps beautiful; certainly free from these ridiculous mannerisms. […] One ought to be able to make a heart-rending novel out of the history of a woman such as she” (31-32). This theme of outward transformations runs throughout the novel, as Bennett focuses on the girls’ youth and vitality in Book 1 and on their aged frailty in Book 4. The theme comes to a head in Sophia’s viewing of the body of her late husband, whom she hasn’t seen for decades, when she’s struck by the ravages of time upon his frame. Shortly thereafter, Constance is also struck by the disjunction between youth and old age when she views the sleeping form of the young Lily and then of her aged sister:

She was drenched, as she gazed at Sophia’s body, not by pity for herself, but by compassion for the immense disaster of her sister’s life. Sophia’s charm and Sophia’s beauty—what profit had they been to their owner? (585).