He just needed to find the right combination of factors that would allow him to withdraw the soul from her head without killing her.
You will then look to see what other factors they all have in common.
Those factors went together like sulfur and a spark.
There were too many paths and factors, though all seemed to lead to one of two futures.
The theory underlying hepatoscopy therefore consists of these two factors: the belief (I) that the liver is the seat of life, or, to put it more succinctly, what was currently regarded as the soul of the animal; and (2) that the liver of the sacrificial animal, by virtue of its acceptance on the part of the god, took on the same character as the soul of the god to whom it was offered.