Classical texts say that the Moon has no enemies. This would make sense because the Moon represents the Mother, and nobody is an enemy of their Mother.
When we say, “The Moon has no enemies,” does it mean
(A) the Moon hates no planet, or
(B) no planet hates the Moon, or
Most astrologers will say the answer is “B.” In my opinion, that’s wrong. I say the answer is “A” (The Moon hates no planet)
The more popular idea that the answer is “B” (No planet hates the Moon) seems based on a bad translation (based on unclear wording in the original) of the BPHS text which deals with the topic (3.55 in the Girish Chand Sharma version). Here is my explanation of the complete text. The conclusion I draw by analyzing this text is that the Moon is friendly to Mercury, but Mercury is inimical to the Moon.
This is a very dramatic non-reciprocal relationship, so let’s focus on it to understand why I feel the answer above is “A” and not “B.”
As you noted, the Moon represents the mother. I agree with you that it is difficult for a child to be inimical to their mother, but biological nature itself makes it even harder for a mother to be the enemy of her child (the mother’s breast feeds the child). This illustrates that the better answer is “A” (the Moon hates no planet).
Another way to illustrate this is to consider that the Moon symbolizes older women. Older women do have the significant benefit of experience, but don’t often feel confident that this offsets the decline of their youthful sexual attractiveness. People who do not feel sexually attractive tend to lose self-confidence. Without confidence in our ability to achieve something great, we becomes non-discriminating about the partners we are willing to accept. Yet, the feminine nature is also not often willing to be without a partner entirely. So the older feminine nature (the Moon) is willing to establish friendship with anyone who is also willing.
Yet another way to look at this is that the older woman (Moon) is Queen-like. The queen is pragmatic. She establishes friendship and enmity not on prejudice but on how others initiate and act in relationships. Those who approach her in friendship, she accepts as friends, and those who approach in enmity, she takes as enemies.
All the above show that the correct answer to the question is “A” (the Moon hates no one), not “B” (no one hates the Moon). This is not the commonly held opinion, and will change the outcomes you get when you calculate dignity.
But I have heard that the Moon is an enemy of Mercury. The reasoning given is that Jupiter cursed Moon far having an affair with his wife, causing the Moon to wax and wane. The Moon blamed Mercury, the child born from the illicit affair, for Jupiter’s anger, and hence hates Mercury.
This story is not very sensible, because it depicts the Moon as a very ignorant personality, shifting his own blame unto his child. Gods do have flaws, so this alone does not discount the story. However, please note that there are a few myths about why the Moon waxes and wanes, and the story you have given is not commonly among them. Some tales say it is a curse of Ganesh, but by far most say it is a curse from Dakṣa (given because of the Moon’s orbital slowness in the asterism of Rohiṇī, symbolically representing his unfair preference for one of his 27 consorts).
OK, but Mercury is intellect and Moon is emotion and desire. Desires make the intellect useless. Doesn’t this show that the Moon is a direct enemy of Mercury?
No. What it shows is the exact opposite. Intellect feels bothered by emotions. So it is Mercury (intellect) who does not like the Moon (emotions). Emotions, on the other hand, love intellect, because intellect enables communication, through which emotions express themselves. So the Moon (emotions) needs and favors Mercury (intellect, the communication-enabler).
Why do we do things we know are not so helpful?
Look at Bhagavad Gītā, 3.36. Arjuna asks this exact question.
Krishna’s answer is, “Kāma” (desire). Our ability to make good decisions is confused by our desires. This shows that intellect (Mercury) doesn’t like emotions and desires (Moon). The same is not at all true in the reverse. Desires love the intellect, because the intellect figures out how to fulfill desires. Emotions also love intellect, because intellect knows how to use words and gestures, which allow emotions to reveal and express themselves in full detail. This shows that emotions and desires (Moon) love the communicative intellect (Mercury).