IMHO,
As it said in the song of enligtenment, it says
净五根 得五力 唯证乃知难可测
镜里看形见不难 水中捉月怎拈得
Clean up the five root, then one attain the five power.
when one attain it one will know; otherwise it is very hard to examine what is it.
(analogous to) one can easily see shapes within the mirror
However, how can one scope up the moon within the water?
So, clean up the five root, attain the five power. then one knows. one will see it as as easy as seeing shapes /form within the mirror.
Speculating and trying to define it , is similar to trying to scope up moon within the water.
Enligthenment is an non dual phenomenon not a mental concept or speculation or thought or some state one tries to achive.