"My application was at first fluctuation and uncertain; it gained strength as I proceeded and soon became so ardent and eager that the stars often disappeared in the light of the morning whilst I was yet engaged in my laboratory." Page 49 Frankenstein

One major theme found in this novel is duty (and if you don't believe me look at the nifty sheet of paper given to you from Mr. Costello. Any complaints should be given to him). In this lovely frame story we have the duty/passion/obsession/drive of Walter. The man in search of a pole, and then we have the obsession of Frankie. The way he just wilted away at his work (first seen in the quote above) just hits this theme home. Frankie/Victor neglects his family and relationships FOR SCIENCE!!! *lighting flash* (although lighting is hardly in this book at all, except for a inspiring childhood story). Frankie becomes pale, hungry tired and although he creates life he kills his own. It's this sense of duty to create a perfect race that presses him forward. This sense is also a great trait that pulls Walter and Victor together. They both have this sense of duty, and it is this that gets them in their roles of the story.