“ The only way to get rid of temptation is to yield to it.”
Dr. Jekyll on all appearance was a distinguished person in London --- a physician, member of the upper class, etc.
Dr. J had the urge to explore his “evil” side, to do things that were inappropriate and unacceptable; he created the idea that if he invented a potion (drug) that would allow him to act out the evil unacceptable parts of his personality and then hide behind the excuse that it was Hyde not him (fooling first himself, then others such as the lawyer Utterson) --- he could disclaim responsibility for acting that way ---
There are things in life that most people do not want to do ---- most people do not want to give into temptation because they know certain conducts are wrong and evil. While some temptations are moderate such as breaking a diet, some are not such as running over the girl and killing; perhaps Dr. J created his ability to cave into temptation to get rid of it, and then it got carried away; that once he yielded to temptation, he became compelled to continue until the potion would not work on him and would not allow him to go back to resisting and became a part of his Dr J personality. Almost like an addiction to drugs or liquor. As a doctor, he knew that there was risk involved in this experiment and he opened the floodgates to unknown forces that he seemed either to enjoy, to be unable to control or both. These impulses eventually overpowered his personality. Perhaps he just ended up giving in to is inner desires while maintaining the appearances of being a gentleman ---- (example of how in the book he took time out to stay off the potion etc --- I think later he had to take again and then ended up killing?
Can you make an argument that he had two personalities, the potion allowed the evil impulses to come out allowed him to yield to these impulses, allowed himself and others to think it was another person, and eventually when he and the potion could not