In the esoteric philosophy of Thelema, founded by Aleister Crowley in the early 20th century, an Aeon is a period of time defined by distinct spiritual and cultural characteristics, each accompanied by its own forms of magical and religious expression. Thelemites believe that the history of humanity is divided into a series of these Aeons, each governed by a particular deity or archetype that embodies the spiritual formula of the era.
The first of these was the Aeon of Isis, associated with prehistory, a time when humanity revered a Great Goddess, symbolised by the ancient Egyptian deity Isis. This was followed by the Aeon of Osiris, spanning the classical and medieval periods, during which the worship of a singular male god, represented by Osiris, dominated, reflecting patriarchal values.
The current Aeon, known as the Aeon of Horus, is believed to have begun in 1904 with the reception of The Book of the Law (Liber AL vel Legis), which Crowley maintained was dictated to him by a praeterhuman intelligence named Aiwass. The Aeon of Horus, frequently referred to as simply the Aeon and symbolised by the child god Horus, is seen as a time of greater consciousness, individual sovereignty, and spiritual awakening. Thelemites believe that this Aeon represents a departure from the constraints and dogmas of the previous Aeon, particularly the influence of the Abrahamic religions, and heralds an era of self-actualisation and the realisation of human potential.
Within Thelema, each Aeon is characterised by its own specific magical formula, which is fundamental to the practice and understanding of Thelemic Magick. The transition between these Aeons is understood not merely as a change in religious or cultural practices, but as a profound shift in the underlying spiritual paradigm that governs human existence.
The first Aeon, of Isis, was maternal. The female aspect of the Godhead was revered due to a mostly matriarchal society and the idea that "Mother Earth" nourished, clothed and housed man closed in the womb of Matrix. It was characterised by pagan worship of the Mother and Nature. In his Equinox of the Gods Crowley describes this period as "simple, quiet, easy, and pleasant; the material ignores the spiritual."
Lon Milo DuQuette remarked that this aeon was "the Age of the Great Goddess", and that it had originated in prehistory, reaching its zenith at "approximately 2400 B.C." Continuing with this idea, he remarked that this period was when "the cult of the Great Goddess" was truly universal. She was worshipped by countless cultures under myriad names and forms. It would also be a mistake for us to conclude that the magical formula of this period manifested exclusively through the worship of any particular anthropomorphic female deity. For, like every aeon, the magical formula of the Aeon of Isis was founded upon mankind's interpretation of the 'perceived facts' of nature, and our Isian-age progenitors perceived nature as a continuous process of spontaneous growth."
The classical and medieval Aeon of Osiris is considered to be dominated by the paternal principle and the formula of the Dying God. This Aeon was characterized by that of self-sacrifice and submission to the Father God while man spoke of his father and mother. Crowley says of this Aeon in his Heart of the Master:
Crowley also says of the Aeon of Osiris in The Equinox of the Gods:
See main article: Aeon of Horus.
The Aeon of Horus, identified by Crowley as beginning in 1904 with the reception of The Book of the Law, marks the current era in Thelemic philosophy. This aeon emphasizes self-realization, individualism, and the pursuit of one's True Will, symbolized by the child god Horus representing new beginnings and potential growth. Crowley described it as a time of the Crowned and Conquering Child, focusing on spiritual awakening and personal freedom. He also stated, "every man and every woman is a star", highlighting the unique and divine nature of each individual.
Key figures such as Israel Regardie and Kenneth Grant highlight the transformative nature of this aeon, encouraging individuals to embrace their True Will and move beyond previous constraints. Regardie saw it as a shift towards new spiritual and psychological paradigms, while Grant emphasized the break from the restrictions of prior aeons. DuQuette elaborates on the Aeon of Horus as a period of growing individual consciousness and the realization of one's spiritual potential, contrasting it with the Age of Aquarius, which he sees as a smaller aspect of a greater spiritual age. Gunther interprets the Aeon as a time of significant spiritual evolution, driven by the awakening of individual consciousness and the unfolding of the True Will.
The Thelemic calendar uses a unique dating system incorporating Tarot trumps and astrological positions, aligning significant events with corresponding Tarot cards and the positions of the Sun and Moon, reflecting the Thelemic emphasis on synchronizing personal and cosmic cycles. Crowley detailed the practice of recording magical work in his writings on the magical record, emphasizing the importance of documenting spiritual progress.
Aleister Crowley believed that the Aeon of Ma'at will succeed the present one. However, Crowley suggested that the succession of the aeons is not bound to the precession of the equinoxes in his 'Old Comment' to Liber AL chapter III, verse 34, where he states, "Following him [Horus] will arise the Equinox of Ma, the Goddess of Justice, it may be a hundred or ten thousand years from now; for the Computation of Time is not here as There."[1] According to one of Crowley's early students, Charles Stansfeld Jones (a.k.a. Frater Achad), the Aeon of Ma'at has already arrived or overlaps the present Aeon of Horus.
Crowley wrote: