This story represents a concept in Victorian culture, that of the inner conflict of humanity's sense of good and evil.[10] In particular the novella has been interpreted as an examination of the duality of human nature (that good and evil exists in all), and that the failure to accept this tension (to accept the evil or shadow side) results in the evil being projected onto others.[11] Paradoxically in this argument, evil is actually committed in an effort to extinguish the perceived evil that has been projected onto the innocent victims. In Freudian Theory the thoughts and desires banished to the unconscious mind motivate the behavior of the conscious mind. If someone banishes all evil to the unconscious mind in an attempt to be wholly and completely good, it can result in the development of a Mr Hyde-type aspect to that person's character.[11] This failure to accept the tension of duality is related to Christian theology, where Satan's fall from Heaven is due to his refusal to accept that he is a created being (that he has a dual nature) and is not God.[11] This is why in Christianity, pride (to consider oneself as without sin or without evil) is the greatest sin, as it is the precursor to evil itself; it also explains the Christian concept of evil hiding in the light.[11]
Various direct influences have been suggested for Stevenson's interest in the mental condition that separates the sinful from moral self. Among them are the Biblical text of Romans (7:20 "Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it."); the split