Among the Babylonians, the word "liver" was used in hymns and other compositions precisely as we use the word "heart," and Jastrow gives a number of illustrations from Hebrew, Greek and Latin sources illustrating this usage.
The belief arose that through the inspection of this important organ in the sacrificial animal the course of future events could be predicted.
"The life or soul, as the seat of life, in the sacrificial animal is, therefore, the divine element in the animal, and the god in accepting the animal, which is involved in the act of bringing it as an offering to a god, identifies himself with the animal--becomes, as it were, one with it.

The life in the animal is a reflection of his own life, and since the fate of men rests with the gods, if one can succeed in entering into the mind of a god, and thus ascertain what he purposes to do, the key for the solution of the problem as to what the future has in store will have been found.

The liver being the centre of vitality--the seat of the mind, therefore, as well as of the emotions--it becomes in the case of the sacrificial animal, either directly identical with the mind of the god who accepts the animal, or, at all events, a mirror in which the god's mind is reflected; or, to use another figure, a watch regulated to be in sympathetic and perfect accord with a second watch.
If, therefore, one can read the liver of the sacrificial animal, one enters, as it were, into the workshop of the divine will."(15) (15) Morris Jastrow: loc.cit., p.

122.
Hepatoscopy thus became, among the Babylonians, of extraordinary complexity, and the organ of the sheep was studied and figured as early as 3000 B.C.In the divination rites, the lobes, the gall-bladder, the appendages of the upper lobe and the markings were all inspected with unusual care.

The earliest known anatomical model, which is here shown, is the clay model of a sheep's liver with the divination text dating from about 2000 B.C., from which Jastrow has worked out the modern anatomical equivalents of the Babylonian terms.