I tend to side with Francois-Igor Pris who argues that you cannot meaningfully have a philosophy that both includes an objective world and also describes it as dependent upon observation/engagement without it running into an infinite regress.

We can only ever know that our act of observation disturbs a system by comparing it to a more subtle form of observation which presumably does not or perturbs it very little. We know the Hawthorne effect is real because you can compare an experiment where a person is observed in a very obvious way where they are clearly aware of it to one where the observation is secretive, and interviewing them later you can confirm they were not aware of it.

But if we are talking about reality being fundamentally dependent upon observation, then this dependence applies to all observations by definition, and thus there is no such thing as a non-subtle observation that you could compare it to. You could never actually empirically confirm that your act of observation is something that is active that physically alters the system. You would have no control to compare

Indeed, there is kind of an infinite regress here that Pris explains in his book Контекстуальный квантовый реализм и другие интерпретации квантовой механики.

1. If observation is taken to be an active process that alters the system, then the properties of the system are observer-dependent, in the sense that the observed facts depend on an interaction between observer and system. It therefore becomes necessary to explain how this interaction itself gives rise to the definite facts that are observed.
2. But an interaction between two systems cannot, by itself, constitute an observed fact. Any interaction can only be identified as such from the standpoint of a third system relative to which the interaction has determinate features.
3. This third system must itself observe or register the interaction, which again requires an interaction that alters the combined system.
4. If this observation is also treated as an active, perturbing process, then it too requires a further system to account for how it produces definite facts.
5. Repeating this reasoning leads to an infinite regress: every observation that is supposed to produce facts must itself be observed in order to become a fact.
6. Therefore, any theory that treats observation as a physical interaction responsible for generating facts cannot, on its own terms, account for the existence of facts without either an arbitrary stopping point or an infinite regress.

Observation at a fundamental level has to be treated as passive, and thus must always be treated as observer-independent or else it leads to a vicious logical circle.

This does seem a bit strange, because clearly what I observer is different from what you observe, so it seems like there is a kind of “observer-dependence.” But what the philosopher Jocelyn Benoist has argued as well as Pris is that we should distinguish between observer-dependence and contextuality.

If I am sitting on a bench and see a moving train go by, and you are inside the train, we will both perceive the train to be traveling at different velocities. Velocity is sometimes described as “observer-dependence,” but this implies that velocity somehow depends upon the existence of conscious observers and is thus subjective, when this is wrong. Velocity is clearly an objective feature of the world and has no fundamental dependent upon conscious observers, as you can define velocity even relative to inanimate things like a rock that is sitting beside the track.

The physical reality of velocity would be obvious if I stepped onto the tracks in the path of the train. You would not be harmed, as you are riding the train thus its velocity from your perspective is zero, but I would be harmed because the velocity of the train in my perspective is non-zero. No one would be surprised if I got harmed because “velocity is subjective” or “observer-dependent,” we all intuitively understand that velocity is a real, objective feature of the world.

The main premise of “contextual realist” philosophy as Benoist and Pris call it is to remove the anthropomorphic character from this kind of difference in perspective, to stop calling it “observer-dependent” as if conscious observers play some sort of fundamental role here. It is more accurate to call it contextual. You and I perceive the train to travel at different velocities because we are perceiving it under different contexts.

Contextual realism takes all physical properties of the world to be contextual in the sense that they only can be meaningfully assigned an ontology once you specify the context under which it is realized. The train’s velocity, between you and I, is realized in a different context, and so it really is ontologically different. Contextual realism extends this to all things. All of reality is context-dependent, but not observer-dependent. The conscious observer plays no fundamental role, and what they observe is always, on a fundamental level, passive and just identifies what is really there, but what is there depends upon the context under which the observation is made.

Yes. Observation is a natural phenomenon. As such, it is a “property” of the thing being observed, that is to say, observation is self-referential. Therefore even the concept of an objective anything is fundamentally suspect.

There is no evidence to support the existence of “objectivity” - it is a leap of logic, and when I say leap I mean it is a claim that stands apart from evidence and is disconnected from the evidence. It is a presupposition, an axiom arrived at by choice not by reasoning from first principles.

And there is empirical evidence to support that the claim of objectivity is in fact a choice driven by a motivation (as all choices are). If we assume it was a choice, then we would assume there’s a motivation for that choice of creating separation, and we should see that choice being repeated in multiple domains. Lo, where do we find objectivity emerging but in the pre-Socratics of Ancient Greece, the same place we find choice-driven separations in aesthetics (arthroi), metaphysics (waves hand at everything), ethics (virtues), medicine (body as parts instead of body as system), the natural world (biological taxonomies), epistemology, etc.

Objectivity is belief first and then is rationalized post hoc. And we have evidence to support this claim as well. What does psychological research tell us about the behavior of individuals who have post hoc rationalized beliefs when they encounter disagreement? They respond emotionally to protect their psyche. What happened when Europeans - who built their entire civilization integrated with the objectivity of the Ancient Greeks, layer by layer with religion, philosophy, science, politics, and social mores - what happened when they encountered any other civilization that did not center objectivity and instead had more relative, relational, and subjective philosophical approaches to their entire lives? They killed them. They denigrated them. They outlawed their ideas. They ridiculed them and anyone who thought seriously about studying them. They barred people as unfit to practice professions. They suppressed research that was actually sound. In short, they reacted emotionally to protect their individual psyches (and we can go further as say their collective psyche, but some will object to that language).

So, yes. We cannot be certain an objective world exists. It’s not a rejection of the world, but rather a rejection of objectivity. It is those who are emotionally attached to the choice of objectivity via their post hoc rationalization and their deep social insecurity for going against their society’s deeply held beliefs that say “denying objectivity denies the external world”. That’s a non-sequitur. An external world can exist and also not be objective.

Wouldn’t you have to say that there is an objective reality that we’re just simply encoding in our understanding, and that we’re also part of this reality so we can never truly be outside of it and act as “objective” observers? Epistemologically, I agree with the Socratic position (“transcendental"knowledge” is unreachable) and with Descartes (senses can “lie”), but that doesn’t mean, ofc, that we cannot have working, very accurate mental models of reality.