From HPB's Theosophical Glossary, (she prefers to give the opposite order than what is commonly used):
''Nidâna (Sk.). The 12 causes of existence, or a chain of causation, “a concatenation of cause and effect in the whole range of existence through 12 links”. This is the fundamental dogma of Buddhist thought, “the understanding of which solves the riddle of life, revealing the insanity of existence and preparing the mind for Nirvâna”. (Eitel’s Sans. Chin. Dict.) The 12 links stand thus in their enumeration.
(1) Jati, or birth, according to one of the four modes of entering the stream of life and reincarnation—or Chatur Yoni (q.v.), each mode placing the being born in one of the six Gâti (q.v.).
(2) Jarârnarana, or decrepitude and death, following the maturity of the Skandhas (q.v.).
(3) Bhava, the Karmic agent which leads every new sentient being to be born in this or another mode of existence in the Trailokya and Gâti.
(4) Upâdâna, the creative cause of Bhava which thus becomes the cause of Jati which is the effect; and this creative cause is the clinging to life.
( 5) Trishnâ, love, whether pure or impure.
(6) Vêdâna, or sensation; perception by the senses, it is the 5th Skandha.
(7) Sparsa, the sense of touch.
(8) Chadâyatana, the organs of sensation.
(9) Nâmarûpa, personality, i.e., a form with a name to it, the symbol of the unreality of material phenomenal appearances.
(10) Vijnâna, the perfect knowledge of every perceptible thing and of all objects in their concatenation and unity.
(11) Samskâra, action on the plane of illusion.
(12) Avidyâ, lack of true perception, or ignorance. The Nidânas belonging to the most subtle and abstruse doctrines of the Eastern metaphysical system, it is impossible to go into the subject at any greater length.''
In the Transactions of the Blavatsky Lodge, she give a commentary on the Secret Doctrine, stanzan 1.4:
''Nidana means the concatenation of cause and effect; the twelve Nidânas are the enumeration of the chief causes which produce the severest reaction or effects under the Karmic law. Although there is no connection between the terms Nidana and Maya in themselves, Maya being simply illusion, yet if we consider the universe as Maya or illusion, then certainly the Nidânas, as being moral agents in the universe, are included in Maya. It is Maya, illusion or ignorance, which awakens Nidânas; and the cause or causes having been produced, the effects follow according to Karmic law. To take an instance: we all regard ourselves as Units, although essentially we are one indivisible Unit, drops in the ocean of Being, not to be distinguished from other drops. Having then produced this cause, the whole discord of life follows immediately as an effect; in reality it is the endeavor of nature to restore harmony and maintain equilibrium. It is this sense of separateness which is the root of all evil...In the Mahatma Letters to A. P. Sinnett, letter 10 deals with the 12 nidanas as well:
''There they are taught the four noble truths — ariya sakka, and the chain of causation, (the 12 nid[ci]anas) gives them a solution of the problem of the origin and destruction of suffering.
Read the Mahavagga and try to understand not with the prejudiced Western mind but the spirit of intuition and truth what the Fully Enlightened one says in the 1st Khandhaka. Allow me to translate it for you.
"At the time the blessed Buddha was at Uruvella on the shores of the river Nerovigara as he rested under the Boddhi tree of wisdom after he had become Sambuddha, at the end of the seventh day having his mind fixed on the chain of causation he spake thus: 'from Ignorance spring the samkharas of threefold nature — productions of body, of speech, of thought. From the samkharas springs consciousness, from consciousness springs name and form, from this spring the six regions (of the six senses the seventh being the property of but the enlightened); from these springs contact from this sensation; from this springs thirst (or desire, Kama, tanha) from thirst attachment, existence, birth, old age and death, grief, lamentation, suffering, dejection and despair. Again by the destruction of ignorance, the Sankharas are destroyed, and their consciousness name and form, the six regions, contact, sensation, thirst, attachment (selfishness), existence, birth, old age, death, grief, lamentation, suffering, dejection, and despair are destroyed. Such is the cessation of this whole mass of suffering."
Knowing this the blessed one uttered this solemn utterance. "When the real nature of things becomes clear to the meditating Bikshu, then all his doubts fade away since he has learned what is that nature and what its cause. From ignorance spring all the evils. From knowledge comes the cessation of this mass of misery, and then the meditating Brahmana stands dispelling the hosts of Mara like the sun that illuminates the sky."
Meditation here means the superhuman (not supernatural) qualities, or arhatship in its highest of spiritual powers.''