The flesh of the animals which was not used for the sacrifice was usually consumed at the feast which followed the ceremony; this custom was only departed from in the case of sacrifices to the shades of the dead or for purposes of propitiation, and then the flesh which was not burnt was buried or destroyed in some other way, and, in fact, on these occasions many of the ceremonies were of a different kind.
As a rule, another purpose was combined with the sacrifice; it was necessary not only to win the favour of the gods, or atone for some crime, but also to discover the will of the gods by interpretation of signs. Although prayer was called for from all men--from labourer as well as from priest--and sacrifices, though usually offered by priests, could also be performed by others, the interpretation of omens was an art which depended on ancient traditions and knowledge of ritual, and was almost entirely confined to the priests, though, in the nature of things, it could be undertaken by anyone. This mode of prophecy had existed in various forms since the most ancient times. The commonest, though unknown in the time of Homer, was the examination of the entrails, in which the structure, that is, colour, form, and integrity of the inner parts of the victim, especially the liver, gall, etc., were regarded as of fortunate or unfortunate omen. Some anatomical knowledge of the inner parts of animals was therefore indispensable, and in consequence it is natural that this branch of knowledge was kept in the hands of the priests. The older kind of prophecy described in Homer was of a different nature, since it depended on all manner of phenomena appearing during the sacrifice; whether the flame attacked the victim quickly or slowly, whether it burnt clearly, whether it rose upwards, whether it was not put out until the whole animal was consumed, whether the wood crackled loudly, what shape was assumed by the ashes of the victim and of the wood, etc.
Apart from sacrifices, prophecy and divination played a great part in the life and religion of the Greeks. A distinction made by the ancients themselves was between prophecy by art and without art. Prophecy without art was regarded as inspiration of a human being by the divine spirit, and was not dependent on external signs or on the interpretation of an experienced person. There were three kinds: ecstasy, in which the gift of prophecy was communicated to a human being without his own assistance by divine strength and power; dreams, in which the gods revealed directly to men their will or coming events; and thirdly, the oracles, which were of a somewhat different character, being connected with professional prophecy. They were also regarded as direct revelations of the will of the god, so the mode in which this was expressed differed a good deal according to the various oracles; but the questioner was not immediately inspired, as in ecstasy and dreams, but required a mediator, one who was alone able to interpret the revelations of the gods.