The reversal of Doxa ("opinions/metaphysics") and Episteme ("truth/knowledge") happened around the time of the early 20th century. The theory of relativity seems to be the discovery that sparked it, but really this theoretical discover is merely the "best example" of the reversal in knowledge types that I am pointing out.
Once Newtonian physics lost its bearing as being Truth -- which coincided with the scientific method being formulated as a method for truth -- incidentally, we also gradually lost our ability to speak from a position of privileged reality.
This loss happens historically, at the same time in which capitalism as a form of economic, social and political expansion also started to intrude enough on non-capitalist people that such these peoples also began to became capitalist, and started push back. Their entry into the capitalist market bore with it a host of signifiers and meanings that at once altered what was once a solely European narrative. At this time, capitalism as a marker of progress also, in theory, stopped being as such, and started to alter its form to become capitalism without a strong and explicitly European narrative. I don't mean to say that the signifiers of "Enlightenment" or "progress" ever ceased to be relevant, but that such narratives only became secondary to the flow of capital, that making money became primary... that while people still today talk about "progress" and "rationality" such notions are not defined independent of the market place, but only echo it's occurrence, that is, whatever happens in the market place is "rational" rather than rationality being the primary impetus for the flow of resources. The separation of capitalist moves from social narrative's logic forced two effects, which are arguably the same event: 1. Europe (but mostly America) lost its sense of culture as it became the "norm" for capitalism. In other words, American culture became arguably invisible to many Americans. and 2. Capitalism as a system refined/transformed its logic to become able to sustain the creation of its own symbolic Real -- for example, the movements of the financial markets are based solely on itself, without any reference to "real" activity outside of its own sphere.
Whether we want to claim that the scientific revolution sparked this separation when the theory of relativity suggested that reality itself was simply beyond our ability to measure it, that our measurements are mostly, if not purely, self-referential, OR if we want to claim that the influx of non-European cultures caused capitalism to eventually separate from the master narrative of European tradition of progress, the result is really the same.
Either way, we see a separation (parallax gap) between the "outside" happening and the "inside" activity inherent within a logical system/discourse. The result is that when the outside world becomes just a thing, when science or capitalism vanquished the over-coding of traditional narratives onto "things", we get a world full of objects that can become whatever we want them to be. In late capitalism, we are free to manipulate products, produce environments and synthesize an entire new way of interaction with the outside. Blame this on science, or on industry, but when production is hidden from the consumer, through technology, bureaucracy, finance, or any other meaningless Symbolic Real codes that refer only to themselves, we detach from the environment and end up floating in a postmodern sea that constantly spits out signifiers... signifiers that are devoid of any hard points for navigation because we are unchained from any specific environment. In short, the world becomes the reverse imprint of who we are, and what we say.
The implication of this result is best captured by the work of Karl Popper. Although Popper is a scientific philosopher, his work is best characterized as a realization that theories exist solely through their ability to be consistent (ir)regardless of experimental results. A huge question in his work revolves around sophisticated justificationism -- at what point does a scientific theory become unable to be justified? At one "key" experiment (the significance of an experiment always being after discourse has been disrupted by it), or when a theory faces of other completing theories that have more explanatory power?
The basic idea through Popper is that theories have a distinctive "shape" or formative relationship inherent within their primary parts. As this "shape" is extended, it should be able to predict results from experiments not yet performed... of course, various experiments often create auxiliary hypothesises, theoretical asides, until at some point the self referential kernel of the theory can no longer sustain the added modifications, allowing the space for a new theory will come about that will be adopted with a more refined core kernel.
What is revolutionary about this model of scientific theory is that the role of induction is minimum. In fact, Popper insists that induction is not at all needed. This is amazing so let me reiterate: Popper's claim is that science can progress solely on the level of theoretical consistencies. Each competing theory presents a pure sheet of relations, that can be used to over-code the total field of experimental results, both past, present and future. The theory that is the most consistent despite (or because of!) disruptions from other experiments should be the theory that we adopt.
This means that removing theories due to experimental results is only incidental, given the presence of other consistencies. In other words, the primary mode for selecting a theory is its "standing power" <em>in relation to other theories</em>. Experiments and their results are only included as one of the judgments for which theory is most sexy.
What I mean to do now is expand the understanding of consistencies beyond the initial domain of Popper's work and apply it to all relations and all logics of discourse.
There are various theories about the logic of sense. Among them are Hegel, Zizek, Lacan, Saussure, Mikhail Bakhtin, Charles Sanders Pierce, Roland Barthes, Derrida, Roman Jackobson, and Hjelmslev... although the most general of them remain, for me, Deleuze and Guattari. To avoid all this philosophical jargon, I will paraphrase Zizek's use of Lacan, although at times I will interject other terminologies where it may be useful to highlight specific relationships not given in Lacan's meta-language.
All subjectivities/egos/identities (I know the terms are used differently but bear with me) are constructed out of the logic of negation. In the formulation of the ego, through a self-differentiating process analogous to autopoiesis, the self carves a space out of intersubjective symbolic space to understand its role among others. At first, it may want to be belong -- to follow part of the group. Eventually, it may want to lead the group and be recognized as itself.
To also interject the language of Deleuze and Guattari, in the process of autopoiesis, selves carve out vast territories for which there exist collections of intensities, black holes, and other erotified zones. Black holes, in particular, exist as indexical signs (Pierce and Jackobson) that signify/refer to the outside of a system. Such black holes, exist on the territory of the human face, such as the eyes and mouth. In terms of profiles, for a subject, the signifier/d "father" may also cover such a black hole. Such zones are unique to each individual, depending on how they have pushed meaning from term to term. Although individual distinction of such psychial positions may differ depending on a subject, the event of such positions is the effect of autopoiesis as much as it is the intersubjective space differentiating population from population, group from group, or meta-group from meta-group. We create these piles to bracket meaning as a foundation so that we can go about the business of our lives, to create empty space to move freely. The weaker the ego, the less space it carves for itself flourish, and the more easily it is threatened by its own internal inconsistencies (which are also antinomies found in the world, in itself, and in its own immanent verticies).
As Lacan was so quick to point out, through his example of the Edgar Allen Poe's <em>Purloined Letter</em>, the existence of such intensities pre-dates the "accident" of encountering such intensity. If you have issues with your father, you may have created, in the image of your father (and by extension all Fathers) a repository for the entangled meanings that you have discarded. In order to create a clear sense of self, or a clear space for yourself to exist, certain meanings such as being a "loser" or other similar undesirables may be buried inside such intensities, wrapped up in the particular of "father". Such intensities, buried as they are, may be incompletely buried so that they create such a sinthome, that the encounter of a resemblance may bring about again, a threatening of this knot so that the ties of this knot, that hold together the topology of the subject may threaten to become undone. A non-psychoanalytic example of how the creation of such a place in discourse creates the space for the verification of this discourse through its encounter with the outside. Hegel uses the example of a man, Ceasar, to illustrate this. Ceasar created such a revolutionary space for himself so that even after his actual death, that space he created persists under the his moniker. All others after him, would become Ceasar, a subset of being marked as he had been/was/is... and this verification reifies their position as Ceasar, as the centerpiece of Roman political life.
This kind of incidental verification occurs often, beyond scientific theory. In fact, the reaction of individuals that are "out of proportion" with their circumstance bespeak the tripping of such sinthomes since they have encountered (through happenstance), a particular antinomy particular to their identity construct (which is also their singular world view).
The general rule, however, to understanding this is that this merely doesn't happen in regard to individual encounters that are out of proportion... an encounter with an other/object/not-me is always an encounter with discarded meanings, constructs that have been laid aside through autopoiesis. When I see an other, I am actually seeing my construct because I am seeing an other. This isn't to say that our senses deceive us (although they do, on a different level), or that one who is different isn't different in how they appear. But the meaning of what they appear to us, is a meaning that is inscribed in the very heart of how we have created our-self, through either our identification of them, (you are like me, we are of the same/similar group) or our rejection of them (you are not-me, you are an other).
Of course, history and political discourse abounds with such examples, which can be expanded upon later.
The primary extension of this notion of sense, lies in how individuals through political discourse (or discourse in general) are able to weave a super-structure of meaning that is independent but also of, how they encounter the world. In an environment where very little is prized as being key, "the discourse" of different consistencies with different constructs can be brought forward by individuals whose only claim to being true, is the very consistency inherent in the logic of their discourse. Stephen Colbert's "truthiness", as it were. The "facts" as they are, often only function as incidental but "meaningful" accidents that verify/validate discursive claims for-itself. In other words, when you are within a logic of discourse that supports your sense of self, objects will speak to you of their truthiness and seem to mean the things you need them to mean. When you are within a particular consistency, the strength of this consistency will be that you fit the lifeworld and the lifeworld fits you. In short, the illusion is that you (and your view of the lifeworld) are validated by external markers that seem to speak for themselves when in fact you are speaking to yourself what you mean for them to be, and what you mean to be, through them.
This ability of consistencies to swallow "facts" through (invisible) dialogical reasoning is of course, the problem with pundit discourse -- the same fact can be used to deploy alternate/contradictory meanings depending on which discourse it has been deployed in. While statements can be taken out of context, the fault lies less with the original context of the fact itself, than with the differences in context given different discursive logics, different worldviews and different identity constructions that need to be preserved differently.
In other words, even when encountering a beloved, a prized pet, or a car, that beloved is only such because of their place in how you construct the meanings surrounded your own identity. The looser your inscription defining such position that the prized beloved incidentally aligns with, the less meaningful such incidental occupation of such a position will be... and the less pleasure (or pain) you will have when the validation is (or is not) affirmed.
So, "life" affirming memes, or posts, telling you that life is precious, go surround yourself with good, beauty and truth... is really just telling you to create a situation where the positive "hot-spots" in your psychial world are fulfilled by any other who can fill them, while not challenging your world view. In this model, the strong case for discourse consistency is that truth is really only about the you using the outside validating what you've always wished to be the case... not about finding something new. The weaker case for discourse consistency is that truth can only exist when the outside coincides with a position in the psychial consistency... so that the discourse is "useful"... whether that position is desirable or not, is irrelevant.
This ability of the mind to sublimate facts in-itself is not a bad thing... but given the impermanence of even change itself... chances are your consistency is not rugged enough to survive for very long if you venture away from your nest of like minded associates (which given technology, is both easy and hard). The energy it takes to constantly redeploy and maintain such meanings can be very astounding, depending on how desperately you hang onto your identity construction. When you start to understand how you are blinding yourself, when you see your own internal cause is the root of external meaning, most likely you won't be able to identify with such a construct any longer, because you can see how things could be different. When the magic goes away, you won't find any good reason why what was, was at all possible... even if you remember how plausible, wonderful and orderly it all seemed to be.