Evil characters like Isabel, who respect neither the place nor the order of things, are part of the plan, programmed to operate on the principle "that there are no boundaries that cannot be encroached upon, no order that cannot be undone, no law that cannot be rewritten, no virtue that cannot be bought, no body that cannot be possessed, no sacred text that cannot be burned, no pyramid that cannot be destroyed, no opponent that cannot be assassinated." As the most merciless, ambitions, cruel, and sublimely obedient of all the violators, she is the queen of the dark forces, and absolutely necessary, for without the chaos she is destined to maintain, the Universe will end, for it is founded on the opposition between order and chaos. Wars and other conflicts are needed to distract humans and prevent them from progressing too easily and quickly toward Divine Light.

An important component of Esquivel's definition of Love is the capacity to forgive. Most ugly episodes in these characters' lives have been prompted by revenge. Citlali, as a male in 1890, for example, rapes Rodrigo, a female, to avenge Rodrigo's earlier rapes of her. This act is necessary to redeem Rodrigo as well, for he needs to learn what it is to be raped, to feel "powerless ... enraged." A key part of astroanalysis is to state one's true feelings to gain release. Azucena prompts Rodrigo in his therapy session to tell his brother-in-law how he feels about him and to scream out, "I hate you!" Next she has him apologize to Citlali for the pain he caused her in 1521, followed by forgiving the brother-in-law (actually Citlali in a later life) for what he did. The therapy ends with Rodrigo forgiving himself as well.

A similar release marks the final triumph of love in the book, when Azucena forgives Isabel for having abandoned her in the present life and for twice previously trying to have her killed. Isabel's trial ends with her being forced to speak these words: "I promise to abide by and to enforce the Law of Love from this day forward." With this, Rodrigo's and Azucena's memories are restored (the word love spoken by Isabel is the secret password that unlocks their hearts) and their twin-souls are reunited. Peace and love reign.

Meaning of Life The meaning of life in The Law of Love involves a search for universal harmony and peace, which becomes Azucena's quest. In order to achieve harmony, individuals must open their hearts to Divine Love, which, Anacreonte explains, is "infinite. It is everywhere and entirely within reach at every moment.’’ By the end of the novel, Azucena helps the inhabitants of Mexico City regain this peace: "The eyes of all present were able to look deep into the eyes of any other, without apprehension. No barrier existed. The other person was oneself. For a moment, all hearts harbored Divine Love equally. Everyone felt part of a whole. Like a mighty hurricane, love erased every vestige of rancor, of hatred.’’

Flesh vs. Spirit Esquivel defines the Law of Love, which becomes the impetus in the novel for universal peace, as a fusion of the flesh and the spirit, involving a process of reincarnation: "The person who causes an imbalance in the cosmic order is the only one who can restore balance. In nearly all cases, one lifetime is insufficient to achieve that so Nature provides reincarnation in order to give Wreckoncilers the chance to straighten out their screw-ups ... again and again they will be born near each other, until finally they learn how to love. And one day, after perhaps fourteen thousand lives, they will have learned enough about the Law of Love to be allowed to meet their twin soul. This is the highest reward a human being can ever hope for in life.’’ When Azucena meets her twin soul, Rodrigo, their sexual encounter becomes a spiritual experience, as they ‘‘danc[e] through space to the rhythm of the music of the spheres.’’ Azucena achieves a similar state when she has sex with Teo. Then, ‘‘the enjoyment Azucena was experiencing so opened her senses that she was able to perceive Divine Light ... It was not until she was loved that she knew peace.’’

Anger and Hatred The novel chronicles the characters' past crimes against each other, which fills them with anger and hatred and results in a disharmonious universe. As a result several of the characters seek revenge, which creates more suffering. After Rodrigo rapes Citlali and murders her son, she kills his and Isabel's child. In their next reincarnation, a male Citlali rapes a female Rodrigo. After observing this scene, Isabel kills Citlali. In another life, Isabel kills Rodrigo's and Citlali's child (her granddaughter Azucena), because she had been in love with Rodrigo and so was jealous of his love for Citlali.

Change and Transformation The theme of change and transformation is closely linked to another theme in the novel: memory and reminiscence. Change can only occur when the characters force themselves to deal with their painful memories through regression into past lives. Azucena helps them face their suffering and release their anger as a first step in realizing a sense of peace and harmony.

Atonement and Forgiveness The final step in the characters' growth process involves atonement and forgiveness. Through regressions, Azucena encourages Rodrigo, Citlali, and Isabel to give voice to their pent-up anger and so be ready to forgive those who have harmed them. This process also involves the recognition that they have caused others to suffer. In her session with Rodrigo, Azucena helps him regress to two past lives: when Citlali raped him when he was a woman and when he, as a Spanish conquistador, raped her. The first regression teaches him what it feels like to be raped. He is then able to release his feelings of powerlessness and rage. When he subsequently faces what he did to Citlali, he asks her forgiveness and is able to pardon her and himself.