When the Moon develops emotions of attraction to things in the world, the being wants to reach out and enjoy interaction with those things. But that is not possible yet! The being must first develop the capacity to exchange information between the external world and the Sun and Moon’s internal world of consciousness and light. Mercury creates the bridge that allows one world to exchange and interface with the other.
Intellect – The ability to understand things is called “intellect.” The act of “understanding” involves taking a foreign and unfamiliar thing and making it a familiar and integrated part of yourself. To understand something new, you have to carry it across the “bridge,” moving it from a position external and unknown to a position internal and known.
Communication – When understanding operates in reverse, we call it “communication.” To communicate, you start with something inside yourself – an idea, emotion, opinion, etc. – and you carry it across the “bridge” and place it in the external world, where other people can see and understand it themselves. Intellect and communication are two sides of the same coin – and that coin is the domain of Mercury.
Commerce – Because Mercury builds bridges that allow things to be exchanged, he is responsible also for the ability to trade goods and services. In fact, the word “mercantile” and it’s derivatives are based on the word “Mercury.”
The Child – The father (Sun) first gave the seed. The mother (Moon) next nurtured the seed. Now the child is born: the third astrological principle: Mercury. Representing children, Mercury is connected to playfulness, fun games, youth, and pre-pubescent non-sexed behavior, attitudes, and styles.
– Vic DiCara