That fish were, even in the most ancient times, allowed to be eaten on fast days is curious. It is suggested by some students of this subject that the custom came from Syria, and had to do with certain pagan ceremonials and the worship of the fish-god Dagon. It is supposed that some of these early Christians managed, under the guise of a fast of the Church, to maintain an ancient pagan custom and religious rite connected with the Syrian fish-god. The Jews also eat fish on Friday evening—though in both cases the origin of the "fish-eating" was lost sight of in the early centuries of the Christian era. On the other hand, it appears that the worshippers of the fish-god (at any rate, at a remote period) were forbidden to eat fish as being sacred; hence it seems possible that the permission of a fish diet to Christians during days of fasting was given as a means of encouraging those who retained pagan superstitions to ignore and forget them. The supposition that the eating of fish on certain days is a survival of a ceremonial observance connected with fish-worship is the more probable explanation of the custom.
The worship of fish or of a fish-god is one of the outcomes of the old Nature-worship—the cult of Cybele and Rhea, who in the Greek Islands became the great mother Aphrodite born of the sea, and in Syria Ashtaroth (Astarte). She appears also as Atargatis, the Syrian fish-goddess born from a fish's egg, and worshipped at Hierapolis; her worshippers must not eat fish. Dagon, the fish-god of the Philistines, belongs to the same group of mythologic inventions. He was half-fish and half-human, like a merman, and is, in spite of this strange personality identified with the Greek Adonis! The cult of the fish-god was widely spread in ancient Greece, even in Byzantine times, and many Christian converts were devotees of the fish worship. I have on my table a photograph of a life-sized fish modelled in gold which was dug up in 1883 from the shores of a lake near the coasts of the Black Sea. It was at one time supposed to be of mediaeval workmanship, but is now shown to be of ancient Greek workmanship (450 B.C.), and was probably a votive offering connected with the worship of the fish-god.
Then, again, in the ancient Indian story of the Deluge we read of Manu (who is the Noah of that variety of the ancient legend) finding a remarkable young fish in a stream where he is bathing. The young fish (which is really the god Vishnu in disguise) can talk, and requests Manu to take care of it, and promises him if he does so to reveal to him when the deluge is coming on. Manu takes the fish home and rears it. He then is told by the fish to prepare an ark, and place on board useful animals and seeds and then to embark on it with his family. The ark floats away in the flood, guided by the sagacious fish, which seizes a rope and, swimming in front of the ark, tows it to a mountain in Armenia (Ararat!), where the vessel rests whilst the flood goes down.
There was evidently a special cult of the fish in Syria and the East, which spread to Greece and Rome in very early pre-Christian times, and survives in some of the stories in the "Arabian Nights" about human beings being turned into fish. It is not surprising that this cult should have lodged itself by obscure means in the practices of the early Church.
The most remarkable outcome of this is the recognition of the fish as the symbol of Christ. The letters of the Greek name for fish ΙΧΘΥΣ (ichthus) can be interpreted as an acrostic, the component letters of the word taken in order being the first letters of the words Ἰησοῦς Χριστὸς Θεοῦ Υἱός, Σώτηρ (Jesous Christos Theou Uios Soter), which are in English "Jesus Christ Son of God, Saviour." This coincidence enabled the pagan worshippers of the fish-god to make their symbol or "totem" (using that word in a broad sense) the symbol of the Christian religion. Whether the use of the fish and of the letters of the Greek name for it was or was not independently started by the early Christians, its employment must have conciliated the fish-worshipping pagans, and rendered it easy to bring them into the fellowship of the Christian Church. Hence we see that a fish has more to do with Christianity than appears at first sight. It is quite possible that whilst the cult of the fish-god or fish-goddess may have involved at one period of its growth an abstention from the eating of fish or of particular species of fish as being sacred, yet the very ancient belief in "contagious magic" and the acquirement of the qualities of a man or an animal by eating his flesh, may have in the end prevailed and led to the eating of fish, the sacred symbol, on the fast days prescribed by the Church, when a special significance would be attached to such food as was sanctioned.
The evidence of the connexion of the early Christian Church with fish worship becomes convincing when once the importance of the great secret cult of the "Orpheists" and its connexion both with early Christianity and with fish worship is recognized.
It has long been known that there is a special association of the very ancient and primitive Greek cult of Orpheus, with the much later cult of Christianity. Many of the most important doctrines and practices of the widely spread secret society of the Orpheists closely resemble those of Christianity. Carvings and medals of Orpheus bringing all animals to his feet by his music were, by the earliest Christians, adopted as equally well representing Christ the Good Shepherd. But recent discoveries carry the matter much further. Orpheus is one of the names of a mythical hunter and fisherman of prehistoric times, who taught his people music, and by his magic helped them to successful catches of fish, and to the "netting" of beasts, as well as of fish. His followers adopted the fish as their "totem," or sacred animal, and they represented Orpheus (whether known by that or other names) as the warden of the fishes, a fish-god, and himself a fish—"the great fish"—and a "fisher of men." Fishes were kept in his temples and eaten solemnly (at first in the raw condition), in order to transmit to his worshippers his powers.
In Greece, where the cult of Orpheus was introduced by way of Thrace, he became mixed with, or made a substitute for, Dionysus (the wine-god), and the same legends were told about the one as the other. He and his followers are pictured as wearing a fox's skin (supposed by some to have been originally the skin of a sea-fox or shark), and the fable of the fox and the grapes, and the very ancient story of the fox fishing with his tail, belong to the Orpheus legends.
Very ancient peoples, earlier than the Greeks of classical times, habitually adopted some animal as their totem and name-god—as do many savage races to-day. Thus, the Myrmidones of Thessaly had the ant (myrmes) as their totem, the Arcadians the bear (arctos), the Pelasgi, who preceded the other tribes in Greece—the stork (pelargos). It is now suggested that the Hellenes, who succeeded the Pelasgi, and gave their name to Greece (Hellas) and to all its people, were so called from their having the fish (ellos, the mute or silent one, a common term applied to fish) as their "totem," and that they were, in fact, from the first worshippers of the fish-god Orpheus, Di-orphos, Dagon or Adonis! Other "cults" grew up among them. The whole Olympian company of gods and goddesses were fitted out by poets and priests with man-like forms, and with the speech, habits, and passions of humanity. But the old deep-rooted worship of the primeval fisherman who was typified by and identified with "the great fish"—much elaborated by its hymns and mystic ritual, its lore, and its legend—flourished and developed wonderfully in secret, wherever Greeks were found. Its priests were missionaries like the mendicant friars of later days, and it was—in pre-Christian times—the most popular cult not only in Greece and Asia Minor, but also in Southern Italy. Hence it is easy to understand that Christianity, by adopting the fish—the ΙΧΘΥΣ—as its emblem, readily received sympathy and converts from the Orpheists, and that the solemn rite of eating the fish on appointed days was established. Hence it seems to have come about that the early Christian Church permitted the eating of fish on most (but not on all) fast days.