What exactly is the nature of this illumination? As I said before, this question has been left unanswered by Buddha. It has not been answered by his immediate disciples either; but they have given some description of it in negative terms, as the cessation of craving, of the grasping ego, of ignorance and delusion, and this silence regarding the nature of the unconditioned, impersonal state and its description in negative terms or even through silence is perfectly Vedantic. But it was sought to be answered in more positive language by later followers who had split up the movement on various grounds into eighteen sects within a century of the Master’s death. Thus it was from the later followers’ formulation of answers to a question on which Buddha himself and his immediate disciples had kept silent that all the confusion and misunderstanding regarding Buddhism has arisen in our country.
Let us try to understand the content of that realization in the words of the Master himself. In his very first discourse at Sarnath, Buddha expressed the content of that realization in these few simple words (Majjhima Nikdya, Sutta 26, adapted from J.G. Jenning’s translation):
‘There (at Uruvela) I settled, Bhikkhus, there being everything needed for effort. And being myself subjected to earthly existence, I perceived the wretchedness of what is subjected to earthly existence, and seeking the supreme peace of nibbanam not affected by earthly existence. Being myself subjected to decay, to disease, to death, to grief, (and) defilement, I attained the supreme peace of nibbanam not affected by decay, ---- disease, death, grief, (and) defilement.
‘And the knowledge (jnanam) now as a thing seen arose in me: “My liberation (vimutti) is established, separate existence” is terminated here; there is not now rebirth (punna-bbhavo).”
Continuing further, Buddha said (ibid., Sutta 36):
“Then I turned my mind to the knowledge of the destruction of the taints (asavas). I knew verily (yathabhiitam) (the four truths): “This is sorrow.” ...”This is the origination of sorrow.” ....”This is the cessation of sorrow.” ... I knew verily: “These are the taints (asavas).”
‘When thus I perceived and understood, my mind (cittam) was liberated from the taint of lust (kama-asava),.....the taint of individuality (bhava-asava); and the taint of ignorance (avijja-asava); and when I was liberated there arose in me the knowledge of my liberation. I knew: “separate existence is ended; the holy life is lived, what must be done is done; there is nothing beyond this.”
This is how Buddha described the content of his realization; and it can easily be mistaken for a passage in any one of the Upanishads. Destruction of the separate ego sense, cessation of birth, attainment of perfect purity and insight -- this is spiritual emancipation according to both Upanishads and Bhagavan Buddha. Both term it mukti or nirvana, a state which ensues when avidya, spiritual blindness, along with all its effects, is completely destroyed. Says the Mundaka Upanishad (II. 2. 8):
‘The knots of the heart are cut asunder, all doubts are dispelled, (the seeds of ) all actions get exhausted, when the supreme truth of Oneness is realized.’
The Buddha had attained the ‘bodhi’, enlightenment, which is ‘bahukalpadur-labha,’ difficult to get even by aeons of struggle. He enjoyed the supreme bliss of this attainment for seven weeks all alone in Buddha Gaya. Then a question arose in his mind: Should he or should he not share this treasure with the world? Initially he was inclined to keep it to himself; and for good reasons; for the worldly-minded cannot comprehend it, and it would be mere vexation of spirit to teach it to them. But the god Brahma intervened on behalf of the world, and Buddha agreed to communicate his realizations, ‘out of compassion for the world’ and the knowledge that there would be some at least who would be pure enough to comprehend so high a teaching. With this resolve, he entered the third and most significant phase of his eventful life.
—This is an excerpt from Dynamic Spirituality for A Globalized World -- A commemorative volume of selections from the works of Swami Ranganathananda, late president of RK Math & Mission