"Only the position or momentum of a particle, but not both, can be known with certainty."
— common knowledge in the quantum realm
The view—that there exists no objective physical reality other than that which is revealed through measurement interpreted in terms of quantum mechanical formalism—remains strangely unassailable to this day.
Causality (the relationship between cause and effect) operates throughout all orders of experience, including both the quantum and macro/micronic levels.
Despite humans having had a sincere interest in their surroundings ever since first being released unto them, they remain at large and unable to process the entirety of the big picture (that they have necessarily been parts of) since their inception into it.
The controlling factors which account for humanity's presence are not limitless, yet to summarize their entire scope seems impossible in human terms. One of the main reasons for this, is that there is usually more than one possible option by which any effect may be caused.
One of humanity's most intriguing aspects has been the fixation on limiting the menu of options that explain their existence through the narrow window of their own worldview. On an individual scale, this is problematic at best towards establishing self-awareness; on a group level—for such enlightenment—it is fatal at least. It is often joked about, concerning homo sapiens sapiens, that humans are the singular creatures in all of known existence who wear shoes.
Despite many advances in both their external sciences and their development of internal cognizance, humans have yet to fully come around to a more refined perception of causation. Despite having been perpetually clued-in throughout history that the list of factors constituting the finer gradation of causative variables in the universe may be infinite at most or endlessly cyclic at least, humanity has yet to surrender completely to the idea that it is but an infinitesimal fraction of the whole organism currently in operation.
While all sapient hominids in the universe define themselves as not only having been introduced to creation separately, furthermore, they cannot function properly without an oblique separation from the growing self-awareness to the contrary that their engineered micro-circuitry engenders over time. That is to say, the ultimate role or function of the paradoxically "self aware" sapient species throughout the universe seems to remain just that: a paradox not merely in the perceptive sense of being limited to gleaning just the surfaces of the reality it is immersed in, but furthermore, a living, existing paradox in defiance of possibility itself.
There exists a key in the comprehension of this dynamic. That key is Paradox itself, which by definition cannot fully be understood (otherwise it would not be paradoxical). In lieu of an enlightened understanding of such oxymoronic truth, the suggestion remains that to accept contradictory information, one must perforce coat that bitter pill 'with a thin layer of faith'—or, at the very least—a workable suspension of disbelief.
Existence itself—being entirely a relative matter—begins to make sense when compared against its alternative, non-existence. Another way of stating this same exact thing is to admit that non-existence makes no sense. Conversely, sense makes existence.
This is how the perceived is revealed to be identical to the one perceiving. This is also how identity itself is revealed to be the perception of existence. Without this dynamic—there can be no existence.
The conclusion this evidence points to is a simple one from the larger perspective of reality, yet from the narrowed perspective of humanity, it remains a largely unprocessed, and therefore staggering conclusion indeed:
There can only be a single real identity in all of creation.
Despite being expressed through a myriad manifestations, the key towards unlocking the gates of comprehension remains the same shape as ever:
It is the very shape of paradox itself.