Many astrologers say Mercury is in a weak position here, implying that the person communicating feels weak or inferior in some way. On a strictly mercurial level, it can make life difficult in numerous ways. However, when Mercury is present, the individual’s imagination is heightened, mental psychic powers are strengthened, and a new level of expression is discovered. According to The Twelfth House: The Horoscope’s Hidden Power:
The gift of attracting certain situations unintentionally has a rather unexpected feature. With planets in the 12th or in aspect to the ruler of the 12th, people can find themselves in situations they have not consciously sought. Such situations can be difficult to escape from and yet, strangely enough, they may turn out to be very agreeable. Thus, people with Mercury in the 12th can engage in writing, journalism, publishing or bookselling, without consciously choosing to do so, or even rather against their will. But this need not be a disaster; in fact, it may give a lot of pleasure. The crux of the matter is that the people feel that life has dumped them somewhere and left them to make the best of it, but it has all turned out well in the end. This is the good side of the 12th house: if these people let things come as they may, it seems they will often be led to do things that promote their best interests.”
This is a good placement for helping individuals with communication. The person knows what it’s like to be overcome by an emotional force so powerful that it obliterates one’s ability to communicate what they’re experiencing. In other words, they can help others navigate the turbulent waters to a better understanding. As a result, the type is ideal for use in dream study, psychology, and understanding the unconscious. They do, however, occasionally suffer from too much knowledge crashing in and out of their heads like waves. It is critical that they learn to block out other people’s thoughts and focus on their own thinking. In order to clear their minds, individuals must protect against intruding thoughts.
With Mercury in the 12th house, a person may believe that others misinterpret what they are saying, causing confusion or miscommunication. The person may be prone to mental anxiety and over-worrying, and is unknowingly attempting to regulate the chaos by being overly ordered. This position of Mercury can manifest physically in an individual, resulting in a learning difficulty, hearing problem, or speaking problem that prevents them from being fully understood. This may make them feel cut off from reality, people, and places, and out of the loop; they may also feel extremely vulnerable about their mental abilities.
This is normal, but it may appear that their thoughts are chaotic, overwhelming, and filled with too much information, making it difficult to get clarity. Perhaps they were bullied for speaking or not speaking, and were constantly advised to stay silent. Perhaps they were made to feel their thoughts had no significance whenever they presented themselves verbally. They may have learned to avoid discussing personal topics and to be afraid of saying anything at all. Much of their worry can be relieved by sharing their deeper insights in some form, and by acknowledging that their perceived flaws may actually be their biggest strengths.
In the 12th, Mercury is so tuned in to the inner experience that it may be difficult for others to understand. There is a strong inclination to fantasize, imagine, and drift off a fair bit of the time. However, the Hermes planet in this position can be gifted in writing, speaking, and other intellectual pursuits. However, there is always a struggle, and the individual may need to unravel their sentiments about why they feel so mentally inferior, and how their upbringing may have played a role in their current state of mind.