Annihilation Complete destruction of consciousness is an impossibility in nature, for there can be no annihilation of the consciousness which makes the essential person. The universe is built of illimitable hosts of evolving entities existing in all-various grades of evolutionary unfoldment. All are passing through a continual series of changes -- comprising the shedding of sheath after sheath -- involving their essential consciousness. These entities continuously modify the vehicles through which they express themselves on the various cosmic planes. When the elements forming a compound become dissociated, the compound as such ceases to exist, at least temporarily; but there still exists that which brought the elements into the compound union. The human personality is constantly changing, even during a single life, and even more greatly through rebirth; indeed, the higher states of individualized consciousnesses, though they may endure for periods so vast as to seem to be everlasting, must disappear for a time during the kosmic pralaya. Even then, when the physical, psychic, and spiritual vehicles are reduced to unity, it is not annihilation any more than a person in dreamless sleep is annihilated while his higher self is in its original state of absolute consciousness, though it leaves no impression on the sleeping and therefore unconscious brain. "Nor is the individuality -- nor even the essence of the personality, if any be left behind -- lost, because re-absorbed. For, however limitless -- from a human standpoint -- the paranirvanic state, it has yet a limit in Eternity. Once reached, the same monad will re-emerge therefrom, as a still higher being, on a far higher plane, to recommence its cycle of perfected activity" (SD 1:266).
Nirvana, then, does not mean utter annihilation, nor did the Buddha teach utter annihilation or wiping out. Thus fundamental consciousness is uninterrupted from eternity to eternity, although undergoing continual change. But such change is not a difference of essence, but a continuously enlarging and ever greater unfolding of the inner essence.