A while back, I was asked what the Moon meant to me, and as I thought about the question, I realized the answer was a suitably good way to start off a new year.
The Moon is the eighteenth card in the Major Arcana of the Tarot, and in its modern incarnation it features a swollen moon hung low over a landscape that is dominated by a river and two towers. Usually a crustacean floats in the river and two canine-like animals sit on the opposite shores of the river, faces lifted toward the moon. Rain (or tears or drops of blood) falls from the Moon. The Thoth deck has nine drops; the Noblet deck has twenty-two.
The Moon typically represents the presence of a secret wildness, an untamed aspect of the querent that lies just below the surface. The two towers are typically said to represent the Pillars of Severity and Mercy, the outer pillars of the Tree of the Sephiroth, and numerological math reduces the card to a “9,” the value for endings. And beginnings.

Aleister Crowley says of the Moon:
One is reminded of the mental echo of subconscious realization, of that supreme iniquity which mystics have constantly celebrated in their accounts of the Dark Night of the Soul. But the best men, the true men, do not consider the matter in such terms at all. Whatever horror may afflict the soul, whatever abominations may excite the loathing of the heart, whatever terrors may assail the mind, the answer is the same at every stage: “How splendid is the Adventure!”
There are all manner of things to be terrified of in the 21st century, and it is easy for us to become wrapped up in being afraid. The Moon forces you to consider that we are children of darkness as much as we are children of light. But the pillars on either side of the river represent hope. They are a reminder that we can react in two ways to the dark water that flows through this card (and through our hearts). There are two paths by which one can ascend the Tree and realize the light of Kether. In every situation, there are two ways to proceed: looking back or looking forward; in fear, or in exaltation. Yes, the Moon fills a dark sky, but its light is a reflection of the sun.
In the Meditations of the Tarot, the anonymous author suggests the Moon is a card of retrograde movement, i.e., one of internal reflection versus external growth. There are, he posits, three lights as manifested by human consciousness: creative light, reflected light, and revealed light. The light of the Moon is the reflected sort, and it concerns itself with the manner in which our intelligence comprehends and classifies that which is considered “matter” (all perceivable objects). He quotes Henri Bergson’s Creative Evolution in a definition of intellect as that faculty which, upon receiving stimuli, considers and formulates a response based on what has gone before. This, then, is the basic principle of existence: like produces like. The Moon, he suggests “in so far as it is a spiritual exercise, has no other aim than to evoke the conscious desire to go further than intelligence, and to decide to make a ‘leap’ in order to leave this sphere.” (Meditations on the Tarot, p. 497.)
There was a full moon on the last day of last year. It seems fortuitous that we end our first, frightful decade of a new millennium with an anomaly. A blue moon. Whatever came before is behind us now, and in those final few hours, we could look up in the sky and freely wonder what comes next.