Historically, I would say that temptation seems to win out more often than not. If we merely look at Hyde's choice to secretly live out his most base instincts, we can easily infer that he knows the difference..... he would be shamed if people knew what he was doing, he would lose social standing, respect, and likely his opportunity to practice his trade. An example of this can be found in Jekyll's relationship with Dr. Lanyon, one of his contempories. Lanyon admits that he and Jekyll severed ties because of a distinct difference of opinion over scientific endeavors.............. obviously, Lanyon kept his reasons to himself, or Jekyll would likely have been ruined.
If we look at modern life, there are numerous forms of addictions that alter the human condition. Alcohol and drugs alter the mind...... as does technology in its many forms. Then consider the addictions of power and greed. Over the course of history, it is evident that temptation of all kinds has had the power to infect and infiltrate societies. What do YOU think it would take to remove it?