BoM/TWS Message Forum

It actually is addressed in the wiki, though parts of the wiki contradict the interactive itself, and like I said in my response to Wordsmitty, this part of the wiki hasn’t been updated in 4 years. The Metaphysics of Magic section of the wiki says this:

Points of difference between essentia and substantia and imago: Substantia cannot be created, destroyed, divided or multiplied; nor can it be altered. Imago cannot be created, destroyed or divided, but it can be altered and multiplied. Essentia cannot be created or multiplied, but it can divided, destroyed and altered.

The division, I must point out, is not like the physical division of a molecule or atom, which will destroy the molecule or atom by changing it into some other molecular or atomic substance. Rather, the division of essentia is actually a mathematical kind of division, in that you get two of them, but each loses a proportional amount of its "reality." Thus, dividing a bit of essentia by two will result in two bits of essentia that are only half as real as the first. (Destroying one of the clones will restore full reality to the survivor.) As it is divided, the essentia becomes less stable; it will not suddenly collapse, but a further division can instantly result in a collapse and the destruction of all the clones. For most people, the safe number is five clones; anything beyond risks a fatal rupture, a rupture that always occurs by the time you've made eight divisions (and usually by the time you've made seven). For Stellae (with one exception), the safe number is twelve, and that's a hard limit: the thirteenth leads to disintegration. The exception are Glundandrans: they get twenty.

Essentia that has been divided will resonate with itself. That is why a golem must obey the person whose essentia went into its making: the essentia it contains is resonating with the essentia inside the master. No bit of essentia is superior to any other bit; neither result after a division is the "original." Rather, it is the presence of anima inside one person that gives that person the ability to dictate to a golem. If the golem had anima, it would be completely independent.