w up systems of days when things might or might not be done with
safety and advantage. There were the great occasions, economic and
astronomical, referred to above, and there were particular occurrences,
such as a death or a defeat, that stamped a day as unlucky. There are
many such beliefs, the origin of which is lost in a remote antiquity.
The ancient civilized nations had their codes of luck. Egypt had a long
list of unlucky days.[1004] In Babylonia onerous restrictions were
imposed on kings, seers, and physicians on certain days (the 7th, 14th,
19th, 21st, 28th) of the sixth and eighth months[1005] (and perhaps of
other months). A brief list of days favorable and unfavorable to work
is given by Hesiod.[1006] The Roman _dies nefasti_, properly
'irreligious days,' were inauspicious, unlucky.[1007] Similar lists of
lucky and unlucky days are found among existing tribes,[1008] and the
popular luck codes in Christian communities are numerous and
elaborate.[1009] These have done, and still do, great harm by
substituting irrational for rational rules of conduct.

+612+. In many of the cases cited above and in many totemistic
regulations there are prohibitions of particular sorts of food. Such
prohibitions, very numerous, are found in all grades of
civilization.[1010] They have arisen from various causes--climatic
conditions, hygienic beliefs, religious conceptions (as, for example,
the recognition of the sacred character of certain animals, and the
connection of certain foods with supernatural beings and
ceremonies[1011]), sometimes, perhaps, from accidental experiences; the
history of most of the particular usages escapes us. The fundamental
principle involved is the identity of the food with him who eats
it--when it is charged with supernatural power (by its own sacredness,
or by its connection with a sacred person, or by ecclesiastical decree)
it becomes malefic to an unauthorized person who partakes of it.

+613+. A peculiar form of prohibition of foods appears when a society is
divided into groups that are kept apart from one another by social and
religious traditions that have hardened into civic rules. In such cases
the diet of every group may be regulated by law, and it may become
dangerous and abhorrent for a superior to eat what has been touched by
an inferior. The best example of this sort of organization is the Hindu
system of castes, which has a marked and unhappy effect on the life of
the people.[1012] All s