I see that it was still February when I said it was the Full Moon in March. But there is a three-day orb for the full moon, according popular Pagan custom, so it should not matter much which day I noticed it. Although the old man who first taught me the Craft did not believe this. "Either the moon is full or it isn't," he said.

There technically is only a precise and fleeting moment when it's truly full, not nearly enough time for all the things Witches do about it. I suppose he meant either it looks really full or it doesn't, but that is a subjective and variable perception, like the quickening of a child.

I found Yeats' "A Full Moon in March," though not my paper about it. Here is the end, which I remember having to deliver in a monotonous atonal chant. The director wanted to do it the way Yeats intended it. Yeats was not much of a playwright, and even less of a director. And even for poetry, he did considerably better on many occasions:

Why must those holy, haughty feet descend
From emblematic niches, and what hand
Ran that delicate raddle through their white?
My heart is broken, yet must understand
What do they seek for? Why must they descend?

For descecration, and the lover's night.

I cannot face that emblem of the moon
Nor eyelids that the unmixed heavens dart,
Nor stand upon my feet, so great a fright
Descends upon my savage, sunlit heart.
What can she lack, whose emblem is the moon?

But desecration and the lover's night.

Delight my heart with sound; speak yet again.
But look and look with understanding eyes
Upon the pitchers that they carry; tight
Therein all time's completed treasure is:
What do they lack? O, cry it out again

But desecration and the lover's night.

So it's about descration, not purification. Or maybe that's just one of the things that Witches turn inside out, along with darkness and light, God and Devil, and with black cats and toads and spiders all being good luck. And thirteen a fortunate number, a full coven. Which Jesus of Nazareth had, actually. It only came to be thought unlucky because there was one who betrayed him, which is not our problem. Purification and desecration could be the same thing, depending on who you ask, and when.