It was his experience as a psychologist that prompted Jung to note the importance of religious symbolism and mythology. It was evident that across ethnicities and cultures, the language of the subconscious was largely mythological. These symbols become evident in visions, dreams, hypnogogic/hypnopompic imagery, and even in delusions. But, as Jung notes here, certain mythological symbols, the snake for instance, may show up in various contexts that may influence the overall meaning of a particular symbol. That symbol will usually still retain some set meanings that make it unarbitrary when utilized by the subconscious. Since these symbols are not arbitrary, they can be decrypted.
Here, Jung and Kerenyi specifically discuss the divine child and mother/maiden motif. Because of the ubiquitous and rich nature of these mythological motifs, there is quite a bit that they are able to say about them. The main thing I want to comment on here is one of the important facets of Jung's psychological system: the animus and anima. He discusses that quite a bit here because of it's relevance to the above motifs. In Jung's theory of the anima/animus there is the notion that the self is a duality. In a male, the subconscious self is feminine i.e. the anima. In a female the relationship is reversed and the subconscious self is the animus. In connection to his concept of anima/animus, he specifically notes the mythological motif of hermaphroditism. I found this particularly relevant to the current bent of society where some people honestly believe that gender is a spectrum. The notion is delusional, of course, but it's interesting that here we have a societal delusion that Jung almost predicted when he noted the importance of the mythological motif of hermaphroditism, and it relates to some degree to his theory of anima/animus. I have often thought that transgenderism (and maybe to a degree homosexuality) may relate to Jung's concept of the anima and animus. In a normal process of development, a man and woman integrate that subconscious self where it takes its properly assigned role in creativity and in other more intuitive aspects of life, but the conscious self still retains its proper gender identity and everything that relates to that. When the process does not proceed normally, it seems likely that the conscious self takes on attributes of that subconscious self, e.g. possibly through homosexual attraction, and possibly even direct identification with the opposite gender resulting in dysphoria. That is just my take on it. It would have been interesting to see how Jung would've reacted to the current delusional trend regarding gender. As I said, he seemed to have predicted its possible occurrence when he noted how important the symbol and archetype of the hermaphrodite was.
This is a rather short work, and, in truth, Jung's material is already contained in his work Archetypes and the Collective Unconscious. I hadn't read Karl Kerenyi before, but his contribution was interesting as well. All in all an interesting book. I give it around 4 stars.