Law of Cycles

This process of evolution does not proceed in a straight line (as modern science proposes) but in cycles:

As the Theosophist has no desire to play at being a squirrel upon its revolving wheel, he must refuse to follow the lead of the materialists. He, at any rate, knows that the revolutions of the physical world are, according to the ancient doctrine, attended by like revolutions in the world of intellect, for the spiritual evolution in the universe proceeds in cycles, like the physical one. Do we not see in history a regular alternation of ebb and flow in the tide of human progress? Do we not see in history, and even find this within our own experience, that the great kingdoms of the world, after reaching the culmination of their greatness, descend again, in accordance with the same law by which they ascended? till, having reached the lowest point, humanity reasserts itself and mounts up once more, the height of its attainment being, by this law of ascending progression by cycles, somewhat higher than the point from which it had before descended. Kingdoms and empires are under the same cyclic laws as planets, races, and everything else in Kosmos.

In fact, the whole universe undergoes a cyclic process of creation and dissolution which in Hindu thought is 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.

Manvantara

Manvantara or Manuantara is a Sanskrit term which literally means "between Manus." H. P. Blavatsky defines it as "a period of manifestation, as opposed to Pralaya (dissolution or rest); the term is applied to various cycles, especially to a Day of Brahma--4,320,000,000 Solar years--and to the reign of one Manu--308,448,000--.

This concept is based on a cyclic model of the universe of alternating phases of creation and dissolution:

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.

There are different manvantaras according to the cycle of evolution in course:

There were several "Great Ages" mentioned by the ancients. In India it embraced the whole Maha-Manvantara, the "Age of Brahma," each "Day" of which represents the Life Cycle of a chain, i. e., it embraces a period of Seven Rounds (vide "Esoteric Buddhism," by A. P. Sinnett). Thus while a "Day" and a "Night" represent, as Manvantara and Pralaya, 8,640,000,000 years, an "age" lasts through a period of 311,040,000,000,000; after which the Pralaya or dissolution of the universe becomes universal. With the Egyptian and Greeks the "Great Age" referred only to the Tropical, or Sidereal year, the duration of which is 25,868 solar years. Of the complete age--that of the Gods--they said nothing, as it was a matter to be discussed and divulged only at the Mysteries, and during the Initiation Ceremonies. The "Great Age" of the Chaldees was the same in figures as that of the Hindus.

Pralaya

Pralaya is a Sanskrit word that means "dissolution" or "melting away" (from laya: "to dissolve" and pra "away"). In Hinduism it refers to a period where the universe is in a state of non-existence, which happens when the three gunas or qualities of matter are in perfect balance. The idea of pralaya is part of a cyclic model of the universe (present in several Eastern philosophies as well as in Theosophy) where the cosmos is said to appear and disappear regularly within the Absolute Reality:

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.

In Hinduism

Pralaya is of four kinds: a) Naimittaka or occasional, b) Prakrittika or elemental, c) Atyantika or absolute, and d) Nitya or perpetual.

The Vishnu Purana describes three kinds of pralaya:

a) Naimittika is described as the intervals of Brahma's days, when the sovereign of the world rests in sleep. This involves the destruction of creatures, though not of the substance of the world, occurring during his night.

b) Prakrittika or elemental is when the mundane egg resolves into the primary element from whence it was derived. It occurs at the end of Brahma's life.

c) Atyantika is individual annihilation or Moksha. Moksha is the exclusion forever from future existence. It is described as the absolute non-existence of the world, is the absorption of the sage through knowledge, into the supreme spirit.

The Bhagavad Gita describes a fourth kind of pralaya:

d) Nitya or the constant dissolution of all that is born. This is the imperceptible change that all things suffer, in the various stages of growth and decay, life and death. The various conditions of beings subject to change are occasioned by that constant dissolution of life, which is rapidly produced by the resistless stream of time, taking everything perpetually away.

In Theosophy

The Theosophical view of pralaya is similar in many aspects to that of Hinduism, although there are some other pralayas not mentioned in the Hindu literature. Mme. Blavatsky explains:

There are many kinds of Pralaya, but three chief ones are specially mentioned in old Hindu books. The first is called NAIMITTIKA "occasional" or "incidental", caused by the intervals of "Brahmâ’s Days"; it is the destruction of creatures, of all that lives and has a form, but not of the substance which remains in statu quo till the new DAWN in that "Night". The other is called PRAKRITIKA, and occurs at the end of the Age or Life of Brahma, when everything that exists is resolved into the primal element, to be remodelled at the end of that longer night. But the third, ATYANTIKA, does not concern the Worlds or the Universe, but only the individualities of some people; it is thus individual pralaya or NIRVANA; after having reached which, there is no more future existence possible, no rebirth till after the Maha Pralaya.

In Theosophy the different pralayas are connected with the teachings about cyclic evolution through rounds and chains:

Occultism divides the periods of Rest (Pralaya) into several kinds; there is the individual pralaya of each Globe, as humanity and life pass on to the next; seven minor Pralayas in each Round; the planetary Pralaya, when seven Rounds are completed; the Solar Pralaya, when the whole system is at an end; and finally the Universal Maha—or Brahmâ—Pralaya at the close of the "Age of Brahmâ." These are the three chief pralayas or “destruction periods.” There are many other minor ones, but with these we are not concerned at present.

Duration of cycles

When talking about chronology of evolutionary cycles, H. P. Blavatsky frequently used the Hindu one, claiming that it is the closest to the occult chronology. Thus, she explained that the Naimittika pralaya or Night of Brahmâ lasts approximately 4,320,000,000 years, while the Maha-pralaya at the end of an Age of Brahmâ lasts for about 311,040,000,000,000 years.