1.  Mercury was the messenger of the gods, and the planet is the fastest in motion. It moves back and forth through the sky, changing its apparent direction six times each year. This apparent back and forth movement is a reflection of how we learn. We listen, then we try. We go back to correct a pattern and we try again. Once we grasp a concept we can move forward quickly to the next challenge.

Our mental processes have two basic patterns. Inductive reasoning is something we are born with. It is the capacity to remember an experience and apply it to future situations. “Once burned, twice shy” is one way of looking at inductive reasoning. The other is deductive reasoning. This is the ability to take a number of observations and draw conclusions from the information. This is the ability of abstract thought. Statistical research has inductive qualities. If we ask ten people if they like a certain candy and six say yes, we tend to assume that 60 out of a hundred will like it too. Sherlock Holmes used deductive reasoning, putting several seemingly unrelated facts together to learn about his quarry.

Mercury provides us with a specific path for both kinds of reasoning, based on its sign and house placement. And Mercury, more than any other planet, takes on the attributes of its sign, house and aspects. Just as the god Mercury delivered a message without changing it, Mercury in your chart shows how you deliver your personal message. The sign shows your personal bias—how you typically choose to express yourself—and the house shows the area of life in which self-expression is the most important to you.

Mercury in your chart has to do with all kinds of communication. It shows the speed and quality. It indicates how you use the senses. It shows the area of your life where the reasoning processes can best be exercised. Thus it shows where you are likely to achieve the clearest and most potent expression of your inner thoughts to others. Aspects from other planets show how your communication is influenced by the events and people around you.

2.  (Alchemy) The alchemical element described as fluid, creative, uniting, and neutral or androgynous.