Mysteries. Greek teletai, or finishings, celebrations of initiation or the Mysteries. They were observances, generally kept secret from the profane and uninitiated, in which were taught by dramatic representation and other methods, the origin of things, the nature of the human spirit, its relation to the body, and the method of its purification and restoration to higher life. Physical science, medicine, the laws of music, divination, were all taught in the same manner. The Hippocratic oath was but a mystic obligation. Hippocrates was a priest of Asklepios, some of whose writings chanced to become public. But the Asklepiades were initiates of the Æsculapian serpent-worship, as the Bacchantes were of the Dionysia; and both rites were eventually incorporated with the Eleusinia. The Sacred Mysteries were enacted in the ancient Temples by the initiated Hierophants for the benefit and instruction of the candidates. The most solemn and occult Mysteries were certainly those which were performed in Egypt by “the band of secret-keepers,” as Mr. Bonwick calls the Hierophants. Maurice describes their nature very graphically in a few lines. Speaking of the Mysteries performed in Philæ (the Nile-island), he says that “it was in these gloomy caverns that the grand and mystic arcana of the goddess (Isis) were unfolded to the adoring aspirant, while the solemn hymn of initiation resounded through the long extent of these stony recesses.” The word “mysteries” is derived from the Greek muô, “to close the mouth,” and every symbol connected with them had, a hidden meaning. As Plato and many other sages of antiquity affirm, the Mysteries were highly religious, moral and beneficent as a school of ethics. The Grecian mysteries, those of Ceres and Bacchus, were only imitations of the Egyptian; and the author of Egyptian Belief and Modern Thought, informs us that our own “word chapel or capella is said to be the Caph-El or college of El, the Solar divinity.” The well-known Kabiri are associated with the Mysteries. In short, the Mysteries were in every country a series of dramatic performances, in which the mysteries of cosmogony and nature, in general, were personified by the priests and neophytes, who enacted the part of various gods and goddesses, repeating supposed scenes (allegories) from their respective lives. These were explained in their hidden meaning to the candidates for initiation, and incorporated into philosophical doctrines.

Samothrace (Gr.). An island famous for its Mysteries, perhaps the oldest ever established in our present race. The Samothracian Mysteries were renowned all over the world.

Eleusinia (Gr.). The Eleusinian Mysteries were the most famous and the most ancient of all the Greek Mysteries (save the Samothracian), and were celebrated near the hamlet of Eleusis, not far from Athens. Epiphanius traces them to the days of Inachos (1800 b.c.), founded, as another version has it, by Eumolpus, a King of Thrace and a Hierophant. They were celebrated in honour of Demeter, the Greek Ceres and the Egyptian Isis; and the last act of the performance referred to a sacrificial victim of atonement and a resurrection, when the Initiate was admitted to the highest degree of “Epopt” (q.v.). The festival of the Mysteries began in the month of Boedromion (September), the time of grape-gathering, and lasted from the 15th to the 22nd, seven days. The Hebrew feast of Tabernacles, the feast of Ingatherings, in the month of Ethanim (the seventh), also began on the 15th and ended on the 22nd of that month. The name of the month (Ethanim) is derived, according to some, from Adonim, Adonia, Attenim, Ethanim, and was in honour of Adonaï or Adonis (Thammuz), whose death was lamented by the Hebrews in the groves of Bethlehem. The sacrifice of both “Bread and Wine” was performed before the Mysteries of initiation, and during the ceremony the mysteries were divulged to the candidates from the petroma, a kind of book made of two stone tablets (petrai), joined at one side and made to open like a volume. (See Isis Unveiled II., pp. 44 and 91, et seq., for further explanations.)

Orphic Mysteries or Orphica (Gr.). These followed, but differed greatly from, the mysteries of Bacchus. The system of Orpheus is one of the purest morality and of severe asceticism. The theology taught by him is again purely Indian. With him the divine Essence is inseparable from whatever is in the infinite universe, all forms being concealed from all eternity in It. At determined periods these forms are manifested from the divine Essence or manifest themselves. Thus through this law of emanation (or evolution) all things participate in this Essence, and are parts and members instinct with divine nature, which is omnipresent. All things having proceeded from, must necessarily return into it; and therefore, innumerable transmigrations or reincarnations and purifications are needed before this final consummation can take place. This is pure Vedânta philosophy. Again, the Orphic Brotherhood ate no animal food and wore white linen garments, and had many ceremonies like those of the Brahmans.

Orpheus (Gr.). Lit., the “tawny one.” Mythology makes him the son of Æager and the muse Calliope. Esoteric tradition identifies him with Arjuna, the son of Indra and the disciple of Krishna. He went round the world teaching the nations wisdom and sciences, and establishing mysteries. The very story of his losing his Eurydice and finding her in the underworld or Hades, is another point of resemblance with the story of Arjuna, who goes to Pâtâla (Hades or hell, but in reality the Antipodes or America) and finds there and marries Ulupi, the daughter of the Nâga king. This is as suggestive as the fact that he was considered dark in complexion even by the Greeks, who were never very fair-skinned themselves.

— H. P. Blavatsky, Theosophical Glossary


The Samothracian Mysteries

Theoroi and Initiates in Samothrace: The Epigraphical Evidence, by Nora Mitkova Dimitrova (2008)
Theoi Megaloi: The Cult of the Great Gods at Samothrace, by Susan Guettel Cole (1984)
Samothrace: A Guide to the Excavations and the Museum, by Karl Lehmann (1955)
Samothrace.  Excavations Conducted by the Institute of Fine Arts of New York University, Vol. 1-12 (1959-)
The Colonization of Samothrace, by A.J. Graham
An Archaic Inscription from Samothrace, by Nora Mitkova Dimitrova and Kevin Clinton
Selected Bibliography for the Sanctuary of the Great Gods, Samothrace
Carl Fredrich & Friedrich Hiller, Inscriptiones Graecae XII.8 & XII.

Samothrace: Framing the Mysteries in the Sanctuary of the Great Gods (Emory University)
Samothracian Networks (Emory University, Scholarly Blogs)

Samothracian Temple Complex (wiki)
Cabeiri (wiki)

Theosophical References: SD 2:3-4, 2:106, 2:362, 2:390 etc., 2:760.

The Eleusinian Mysteries

Initiation into the Eleusinian Mysteries: A “Thin” Description, by Jan N. Bremmer (2011), [published in: C.H. Bull et al. (eds), Mystery and Secrecy in the Nag Hammadi Collection and Other Ancient Literature: Ideas and Practices,2011, 375-97]
The Eleusinian Mysteries: The Rites of Demeter, by Joshua J. Mark (2012) [Ancient History Encyclopedia]

A Dissertation on the Eleusinian and Bacchic Mysteries, by Thomas Taylor (1816)
Essay on the Mysteries of Eleusis, by Sergei Semenovich Uvarov, tr. J.D. Price (1817)
The Eleusinian Mysteries and Rites, by Dudley Wright (1919)
Eleusis and the Eleusinian Mysteries, by George E. Mylonas (1974)
Eleusis: Archetypal Image of Mother and Daughter, by Karl Kerényi (1991)

Mysteries at Eleusis: Images of Inscriptions (Cornell University)

The Eleusinian Mysteries (wiki)

Theosophical References: Isis 2:44, 2:90, 2:98-99, 2:138, 2:145-46, 2:254.

The Orphic Mysteries

On several particulars of the Orphic Mysteries and how they differ from the popular rites and mythology of Greece,” from History of the literature of ancient Greece, by Carl Otfried Müller (1847), pp. 231-238.
The Hymns of Orpheus, translated by Thomas Taylor
A Dissertation on the Life and Theology of Orpheus, by Thomas Taylor
Orpheus, by G.R.S. Mead (original scan pdf | html)

Theosophical References: Isis 1:341, 2:129, …


The Mystery Schools, by Grace F. Knoche

Philosophy and Theurgy in Late Antiquity, by Algis Uzdavinys


Selected Articles, Commentaries, etc.

For more on Greek Philosophy, see:

The Pythagorean School
The Platonic Academy
The Neoplatonists
The Writings of Thomas Taylor