The subject is the person, not one placement
The 8th and 12th houses are often associated with depth, hidden processes and the unconscious. But human questions also arise through identity, resources, communication, family, creativity, work, relationships, vocation and community.
A house can indicate a research doorway
A person may enter SPI through self-reconstruction, value and money, language, family systems, children, organisation, partnership, theory, leadership or collective life. The relevant question is what they can observe repeatedly and responsibly.
SPI is a map for sustained study
SPI does not promise that one configuration makes an analyst. It can help a learner identify a field worth developing, while competence still depends on study, evidence, supervision and real work with people.