In primeval times, we are told, sacrifices consisted of meat and drink,
the latter being the "mysterious liquid," water, for which wine was
substituted later on. The ancients roasted millet and pieces of pork;
they made a hole in the ground and scooped the water from it with their
two hands, beating upon an earthen drum with a clay drumstick. Thus they
expressed their reverence for spiritual beings.

"Sacrifices," according to the _Book of Rites_ (Legge's translation),
"should not be frequently repeated. Such frequency is an indication of
importunateness; and importunateness is inconsistent with reverence. Nor
should they be at distant intervals. Such infrequency is indicative
of indifference; and indifference leads to forgetting them altogether.
Therefore the superior man, in harmony with the course of Nature, offers
the sacrifices of spring and autumn. When he treads on the dew which
has descended as hoar-frost he cannot help a feeling of sadness, which
arises in his mind, and which cannot be ascribed to the cold. In spring,
when he treads on the ground, wet with the rains and dews that have
fallen heavily, he cannot avoid being moved by a feeling as if he were
seeing his departed friends. We meet the approach of our friends with
music, and escort them away with sadness, and hence at the sacrifice in
spring we use music, but not at the sacrifice in autumn."

"Sacrifice is not a thing coming to a man from without; it issues from
within him, and has its birth in his heart. When the heart is deeply
moved, expression is given to it by ceremonies; and hence, only men
of ability and virtue can give complete exhibition to the idea of
sacrifice." It was in this sense that Confucius warned his followers not
to sacrifice to spirits which did not belong to them, i.e. to other than
those of their own immediate ancestors. To do otherwise would raise a
suspicion of ulterior motives.