One of the most significant themes of the novel is the sacrifice that Pere Goriot embraces for his daughters and how it is not reciprocated. While the legend of the old man emerges out of conjecture and presupposition, it is evident that Goriot does just about anything for his daughters. He is of the belief that “Some day you will find out that there is far more happiness in another's happiness than in your own.” This theme of unconditional love and support is repudiated in the Paris that surrounds him. In this world, individuals stake their own territory and embrace the reality of upward social mobility. Goriot's daughters are far more concerned with their own potential advancement and name more than they are with their father's devotion. After he has outlasted his usefulness to them, the girls simply move on from it. Balzac develops this theme of love and rejection in Goriot's characterization:
My real life is in my two girls, you see; and so long as they are happy and smartly dressed, and have soft carpets under their feet, what does it matter what clothes I wear or where I lie down of a night? I shall never feel cold so long as they are warm...
Goriot's love for his daughters and the fact that it is never really reciprocated is a reflection of the Parisian world of the time period. It is a realm where social advancement was shown priority over emotional loyalty and connective bonds. This theme of both love and its rejection is of central importance in the novel and relevant to the time period of post- Revolutionary Paris.
Another theme that is evident in the narrative is the collision between urban and rural notions of the good. Rastignac comes form the rural setting and is awed by what he sees in Paris. He is socially awkward, and viewed as an outsider. Through the tutelage of Madame de Beauséant and Vautrin's insight, Rastignac learns how to manipulate people and settings to his advantage. He recognizes that the world his past is no longer the world of the present and his declaration at the end of the novel, a battle between he and the illuminated world of metropolitan Paris, is a reflection of how he has moved from outsider to insider. Rastignac has rejected his own provincial past and has become the embodiment of the urban social climber. His transformation is the embodiment of a condition of life in Paris and French society of the time.