Akshara, the immutable, is one of the technical terms in Vedanta. The history of Vedanta may be considered the history of akshara in a way. The problem has become all the more acute due to interpretational differences. If Adi Shankaracharya has taken it in the sense of maya shakti (power of Bhagavan), Ramanuja has interpreted it as meaning an emancipated soul.
The oldest prose Upanishads teach either akshara (the impersonal,
immutable) or purusha (the person). Mundaka Upanishad tries to reconcile the
impersonal with the personal and the early metrical Upanishads endorse that
stand. The Bhagavad Gita teaches the same doctrine, recognizing two manifest ones
called Natures, namely, a higher one (akshara – mahabrahman VII 5; VIII 20) and
a lower one (kshara – Brahma XV.16; XIV.3; VIII 3-4; III.15; V.10). It is the
lower nature that produces the manifest universe, which is in consonance with the
account presented in Svetasvatara Upanishad, recognizing purusha (the personal)
as higher than akshara (the impersonal) and yet not being distinct from one
another. They are not two, though they are not one either, for they have svagatabheda
(internal differences). Akshara in the Gita (III.15) is the cause of the lower
nature (the Brahman) as one finds it stated in Mundaka Upanishad (1.1.9) and
this lower nature forms the cause of the creation which depends upon karma (the
actions) of the beings. Akshara and purusha are held to be two goals as one
notices in the early metrical Upanishads. The meditations on akshara may reach
the purusha (Bhagavad Gita XII.4), making further progress after reaching akshara.
The Bhagavad Gita does not identify purusha with Brahman. Bhagavan Sri Krishna
is identified with purusha and not at all with Brahman. The lower nature is
said to be the effect of akshara (III.15; IX 7 -10) and the higher nature is eternal
like the purusha and the relation between the two is nothing more than that of
dharma-dharmibhava as one finds it in Svetasvatara Upanishad. The sutrakara
(Badarayana, enunciator of Brahma Sutra) does not subscribe to the view of the
purusha being higher than akshara, for both are one and the same. There cannot,
be according to him, two omnipotent goals and they are the names of one and the
same goal. The Pancharatrins insist on the oneness of akshara and purusha and
advocate that he souls form parts of God and continue as such even during the
period of cosmic rest, which is the stand taken by the votaries of
Vishishtadvaita.
In the literary sense, Akshara means the letters which ultimately constitute the language. There are also important mantras, meant for exclusive contemplation such as ‘namah shivaya’ and ‘om namo narayanaya’ mantra (containing five letters), while the latter is known as ashtakshara mantra. There are also devotional lyrics like the aksharamala, where each verse commences with each of the fifty letters of the Sanskrit language.