Each of the three couples in the novel: Stephen and Dolly, Constantine Levin and Kitty, and Anna and Vronsky, seek to find personal happiness through different means. Each of the couples in some way serve to illustrate the various ways that Tolstoy's individual can be, or fail to be, good, the various ways in which a character can be moral, immoral or amoral through the use of thought, or reason.
Levin grows from the beginning of the novel when his search for happiness was centred on personal fulfillment through marriage. By the end of the novel Levin has reached a sense of personal satisfaction as well as personal salvation through his realisation that love not only necessitates physical love, as that for his wife, but also in a love of God and living for God.
Kitty is young, innocent, virtuous woman – everything that Anna is not. Kitty's happy, wholesome marriage with Levin contrasts in every way with Anna's unhealthy relationship with Karenin and the tortured passion she shares with Vronsky.
In contrast to the growth that Levin experiences is the stagnation of the life of Anna Karenina. Anna begins her search for fulfillment in her affair with Vronsky with a sense of "all for love", just as Levin had begun his pursuit for happiness in a relationship with Kitty. Anna never moves beyond the idea of fulfillment through the physical satisfaction of love. Because Anna's husband, Alexy Alexandrovitch Karenin, cannot satisfy the ideal of love that Anna has set for herself, she must turn elsewhere for the satisfaction that she feels will provide her with a sense of personal fulfillment. For this fulfillment she turns to Vronsky, who she feels because of status can