Shevirat hakelim, the breaking of the vessels, is the best known idea of the Ari's Kabbalah, and the most often distorted. Here is what Etz Chaim says. After the first stages, the Creator brought out ten "points," the Nekudim, which were to become the Sefirot of the world of Emanation. The vessels came out first, then the lights came to enter them. But "those vessels could not bear them and broke." The vessels fell downward, into the place that would later become the world of Creation; the lights, for their part, rose and stood above. This fall, the text specifies, "is called death," for whatever leaves its world to descend into a foreign world is said to die.
Why did the vessels not hold? Because they were still separate, each receiving its light without being linked to the others: isolated points, not an organism. Too great a light in too lonely a vessel, and the vessel gives way. The breaking touched only the seven lower Sefirot, from Chesed to Malkhut. Keter bore the light; of Chokhmah and Binah, only a part fell. The Ari reads all this in a strange passage of Genesis: the list of the kings of Edom "who reigned before a king reigned over the children of Israel," seven of whom "reigned and died." These seven kings who die one after another are, for him, the seven vessels that break one after another.
What remains after the breaking? Shaar HaKlalim answers: the lights rose back to their place, "but some sparks of holiness remained in the vessels," and they fell with the broken vessels. From these fragments "the root of the kelipot was formed," the husks, that is, everything in the world that encloses the good and hides it; the sparks remained captive in them. Etz Chaim counts these sparks: two hundred and eighty-eight, left in the broken vessels to revive them at the time of the repair, as the breath of the bones remains in the buried body until the resurrection.
This story must be read rightly. It is not an accident that took the Creator by surprise: the breaking was necessary so that stronger vessels, linked to one another, could be born afterwards, and so that there would be a real evil to overcome and therefore a real merit to earn. But it is not a fable either: disorder, suffering, beauty mixed with ugliness, are described here as fragments of light that wait.
Keep the double lesson. A vessel that receives alone, without a link to the others, breaks; this is true of the Sefirot, it is true of people. And nothing that fell is lost: each fragment keeps a spark, and the next entry tells how to lift it.