In the Shurangama Sutra, the Buddha says do NOT use your thinking mind which utilizes thoughts, which arise and cease (and so is still within the realm of birth and death) to search for the enlightened Mind of your own Buddha (which does not arise nor cease, is not born and does not die).
If you use your intellectual mind to search for the Buddha, then it will be impossible for you to open the Buddha’s enlightenment. Why? Because enlightenment is not within the realm of logical thought – Attakavacara – it is beyond the realm of thinking.
Despite this, you reach the Buddha’s enlightenment using “that which is aware” of those thoughts. Thoughts arise and cease, but that which aware of those thoughts does not arise nor cease with them:
Ananda, it is impossible while on the cause-ground to use the mind subject to production and extinction as the basis for cultivating in quest of the Buddha vehicle, which is neither produced nor extinguished.
For this reason, you should realize that all existing dharmas in the material world will decay and disappear. Ananda, contemplate the world: what thing is there that will not waste away?
But, has anyone ever heard of the disintegration of the void? Why not? It is because the void does not exist, and so it can never be destroyed.