Henry Jekyll is a Victorian man, he is submitted to a rigid moral and forced, by the society in which he has been educated, to be hypocritical, because he cannot confess what his experiments are really about. Henry Jekyll is nobody's hero, and he is badly judged by Lanyon (he says Jekyll's experiments are "too fanciful") because Lanyon is afraid of the temptation to which Jekyll has succumbed.

Jekyll's primary impulse is fear, he is afraid of his own experiments, because, through them, he discovers some vital truths about himself. He thought that every person had two different personalities, and he wanted to see how each personality would act without being submitted to the other one. As a result of these experiments, the wicked part of himself becomes a "person": Edward Hyde

Because of his strong moral, he is forced to hide his experiments although he might attempt to disguise his experiments under scientific objectivity. Jekyll wants to preserve his reputation, so that he has to conceal his transformations from the eyes of society. By doing this, he is being hypocritical, that is what Robert Louis Stevenson wanted to report about Victorian society.

His experiments separate his two personalities in a strong way: each one becomes a separate being with different realities.

As the experiments go on, Jekyll trespasses the moral barrier, he is violating the foundations of human existence. He becomes a "slave of his own weakness", as all the Victorian men did: they were "prisoners" of the strong morality of the time, as Stevenson wanted to report.

His experiments reveal that everyone has to live with his/her both personalities, because, when Hyde is finally released from Jekyll, commits suicide because he cannot deal with the situation.

So his real sins are:

* going against nature by creating another form of life (Hyde is another being who has not been conceived by natural means),
* going against social morality,
* hiding his experiments from the eyes of his close friends (except Lanyon, who ceases to be his friend since the moment he sees Henry's transformation into Hyde). His friends cannot understand why he is related to such an evil man such as Edward Hyde, and, instead of explaining his reasons to them, he tries to avoid doing it and prefers to continue with his dangerous experiments

and, finally, his biggest sin is not wanting to admit that Hyde is himself.