Despite being intelligent and logical for the most part, Doc is somewhat naive at times about the unknown possible uses of his time machine, initially actively explores the course of the world's future and tries to alter the past or future of the principal characters to improve their lives. However, events lead him to conclude that time travel is too dangerous for mankind. His conviction initially strengthened when he realizes that he has unwittingly altered history by preventing the death of Clara Clayton in 1885; he concludes that the time machine has "caused nothing but disaster" and asks Marty to destroy it once he returns to his own time. Nonetheless, Doc pursues a romantic relationship with Clara despite the risks of further disrupting the timeline.