Law of Cycles

The Law of Cycles postulates a model of the universe where processes, events, or phenomena repeat themselves in a recurring way at fixed periods of time. In her Secret Doctrine, Mme. Blavatsky establishes Three Fundamental Propositions, of which the second one makes reference to the law of cycles. She wrote:

The Eternity of the Universe in toto as a boundless plane; periodically “the playground of numberless Universes incessantly manifesting and disappearing,” called “the manifesting stars,” and the “sparks of Eternity.” “The Eternity of the Pilgrim”† is like a wink of the Eye of Self-Existence (Book of Dzyan.) “The appearance and disappearance of Worlds is like a regular tidal ebb of flux and reflux.” (See Part II., “Days and Nights of Brahma.”) This second assertion of the Secret Doctrine is the absolute universality of that law of periodicity, of flux and reflux, ebb and flow, which physical science has observed and recorded in all departments of nature. An alternation such as that of Day and Night, Life and Death, Sleeping and Waking, is a fact so common, so perfectly universal and without exception, that it is easy to comprehend that in it we see one of the absolutely fundamental laws of the universe.

Cycles take place at all levels--cosmic, planetary, racial, national, etc.:

The [terrestrial] periods which bring around ever-recurring events, begin from the infinitesimally small—say of ten years—rotation and reach to cycles which require 250, 500 700, and 1000 years, to effect their revolution around themselves, and within one another. All are contained within the Mahâ-Yuga, the “Great Age”, which itself revolves between two eternities—the “Pralayas” or Nights of Brahmâ.

The larger cycles affect the whole universe, which undergoes a recurring process of creation and dissolution that in Hindu thought are called manvantara and pralaya:

As the sun arises every morning on our objective horizon out of its (to us) subjective and antipodal space, so does the Universe emerge periodically on the plane of objectivity, issuing from that of subjectivity—the antipodes of the former. This is the "Cycle of Life." And as the sun disappears from our horizon, so does the Universe disappear at regular periods, when the "Universal night" sets in. The Hindoos call such alternations the "Days and Nights of Brahma," or the time of Manvantara and that of Pralaya (dissolution). The Westerns may call them Universal Days and Nights if they prefer.