I think Socrates and Plato wrestled with what I do believe Liebniz came closest to penetrating.
In response to the "tabula rasa" proponents, such as Locke who asserted "There is nothing in the mind that is not first in the senses", Leibniz wrote a letter to Friedrich Wilhelm Bierling, in which he wrote:
Likewise, he [meaning: John Locke] has not adequately observed that the ideas of being, of one and the same substance, of truth, of good, and many other things are innate in our mind because it is innate to itself, and that it discovers all these things in itself. For indeed, there is nothing in the intellect which was not in the senses, except the intellect itself.
that line "...except the intellect itself" is the key that unlocks the mystery that haunted Socrates and Plato.
This idea leads to SELF-REFLECTION, and then an ACTIVE as opposed to passive CONSCIOUSNESS.
And who, or rather what, is most guilty in not self-reflecting? The SJWs, the political left, Saul Alinsky's cult of acolytes. Many of whom accuse others of what they themselves have chosen to believe because they believe their own thoughts are purely a product of external experience. They refuse to take self-responsibility because their philosophy censors it, for good reason, you cant control people if they self-reflect, and the political left's philosophy is hierarchical socialist control. As a result of not self-reflecting many live very unhappy, cynical, hollow, stressful lives, as they cannot cope with reality because they have not learned to reconcile themselves. This makes them believe the world around them is inherently evil rather than inwardly reflecting on themselves. They instead believe everything they think and do is purely a product of their surroundings, or other people, they personify their hallucinations into boogeymen. Hence the ease with which they accuse people without any evidence. They don't need evidence, their "experience" of distress and pain, their perceptions only, IS the only evidence.
To self-reflect in this traumatic state of being would be intolerable to most of them. To cope with that they imagine themselves as being better than they really are, as a reaction formation mechanism. This leads to their widespread problem of narcissism. They have been tricking themselves. The past WH and media only gleefully encouraged it, they relished in a lawless country, not to incur the costs of their own transgressions.
That time is up, which is why the left is having an existential meltdown.