Isaac Asimov challenges the boundary between humans and machines by creating a world with a precariously balanced human population and robots almost indistinguishable from humans. As Lije struggles to solve the murder of Dr. Sarton, he comes face to face with the limits of his nature and the seemingly limitless possibilities for his robot partner, Daneel. The characters’ growth brings Lije, the human race, and Daneel closer to full humanity. Asimov uses this theme as an explanation of humanity’s possibilities.

In the opening chapter, Lije exemplifies the typical man and R. Sammy, the typical robot. Asimov begins the novel with this interaction between Lije and R. Sammy as a demonstration of the complicated and contentious relationship between robots and humans on planet Earth. R. Sammy takes a young man’s job, leaving him declassified and without means. R. Sammy follows the Commissioner’s orders to the letter, causing Lije to become annoyed, telling his boss that “it’s uncomfortable, Commissioner. He tells me you want me and then he stands there” (3). Lije dislikes that he must work with such an unintelligent and annoying creature. The contentious relationship is further shown by the following conversation about Lije’s new partner. He acknowledges that most men “were Medievalists in one way or another.