Answer: the sense of duty toward one's family
Explanation: In these two excerpts of "The Metamorphosis" by Franz Kafka, the theme that both have in common is the sense of duty toward one's family. Gregor always provided money for his family. In the first excerpt, he is proud of being able to provide a comfortable life for his family and is afraid that they may lose it now that he has become an insect. In the second excerpt, he is worried about the unpleasantness he is imposing on his family.