If language is self referential, the there are two ways to think about this. ..................................One way says the world as the world is bound up with the ways we know it; ontology and epistemology cannot be separated and my coffee cup IS a coffee cup AS a bundled phenomenon. The idea of the cup is literally the cup-thing itself. So, I point to my cat, and the pointing, the concept, the predelineation of the past informing the present occasion as well as the anticipation of what the "future cat" will be, do, all of this is constitutive of the occurrent apperception of my cat. All of a piece. Any separation of parts would be an abstraction, which is fine because this is what analysis is, as long as we don't think analytically determined entities ae entities in their own right............................................. Another way is to understand that the knowledge that brings the palpable thing into understanding and familiarity is qualitatively distinct from the palpable thing. To me, this is a very strong and even profound claim. It is not about some noumena that is postulated but beyond sight and sound; it's about the palpable presence of the thing, and its being alien to the understanding, so their you are, confronting metaphysics directly. This is called mysticism. — Constance
I agree that there there are two distinct ways in which we understand the external world, and these may be described in various ways.
1) Metaphysics, our past history, Sartrian existence and Kantian a priori knowledge are all aspects of the same thing. This is, as you say, about "confronting metaphysics directly".
2) Physics, our present situation, Sartrian essence and Kantian a posteriori knowledge are also all aspects of the same thing. This is, as you say, "apperception".
Each is distinct, as hardware is distinct from software, yet both are mutually dependent, and both are required for the proper functioning of the whole human organism.
The colour red is experienced both physically and metaphysically
Consider our experience of the colour red. From physics, I know that the wavelength of red light is 700nm. But I also have a private subjective experience of the colour red, an experience that can never be described to another person. At the moment of having the subjective experience of the colour red, it is not the case that I am observing the colour red, rather, it is the case that I am the experience of the colour red. An experience transcending any physical knowledge into an immediate and visceral metaphysical knowledge.
IE, our knowledge of, for example, the colour red, is both physical and metaphysical
Evolution explains Kant's a priori
We are observers of the external world, yet we are also part of the world. We have an existence upon which we build an essence. This existence did not arise yesterday, or the day we were born, but has been underway for billions of years. We have evolved in synergy with the world. Humans are born with certain innate abilities, in that the brain is not a blank slate, as described by both post-Darwinian "evolutionary aesthetics" and "evolutionary ethics". In the 3.7 billion years of life on earth, complex life forms have evolved to have certain innate intuitions necessary for continued survival. It is not the case that we have certain intuitions and they happen to correspond with the world, rather, our intuitions were created by the world and therefore of necessity correspond with the world. Through the process of evolution the mind gradually models the world around it. If the model had not been correct, then the mind and body would not have survived. Therefore, the sensible intuitions innate within the mind have been created by the world in which the brain has survived.
IE, it is not the case that the mind has an intuition of the world that it exists within, rather, the intuitions of the mind necessarily correspond with the world it exists within, otherwise it would not have been able to successfully survive and evolve.
We understand the world both in a Kantian a priori and a posteriori way
The two distinct ways we relate to the world can be further understood within Kant's theory of the "synthetic a priori". Kant combined the ideas of the Empiricists and the Rationalists. For the Empiricists, such as Hume, only what can be observed has meaning, where a posteriori knowledge is "as mere representations and not as things in themselves"
For the Rationalists, such as Leibniz, understanding is in the mind, where a priori knowledge is "only sensible forms of our intuition, but not determinations given for themselves or conditions of objects as things in themselves".
Empiricism claims that our ideas are fashioned out of experience between an observer and an external world and the ideas thus formed if they have any bearing on external reality then elementary sensations are bound together by some principle of association. Kant argued that on this reading, science could not have developed, yet, as science is successful, the principles of association must have been provided by the observer such that "nothing in a priori knowledge can be ascribed to objects save what the thinking subject derives from itself".
The observer can only understand what they observe if they have a prior ability to experience what they observe, in that we are able to see the colour red but not the infra-red because of our innate abilities. Kant wrote in his
Critique of the Power of Judgement : "We can only cognize objects that we can, in principle, intuit. Consequently, we can only cognize objects in space and time, appearances. We cannot cognize things in themselves". (A239). Foundational to all our understanding of what we observe is our innate understanding of space and time: "Space and time are merely the forms of our sensible intuition of objects. They are not beings that exist independently of our intuition (things in themselves), nor are they properties of, nor relations among, such beings". (A26, A33)
It is true that Kant (1724 to 1804) did not propose an evolutionary mechanism for a priori pure intuitions, as he was not able to benefit from Darwin's (1809 to 1882) theory of evolution, Kant's principle of "synthetic a priori judgements" remains valid.
IE, We are born with certain innate abilities that have taken billions of years to evolve, and based on these innate abilities we can observe the external world, but we can only observe in the world what our innate abilities allow us to observe. Our understanding of the world is from observed phenomenon which are given meaning by a pre-existing and innate understanding of them. The physics of the world is understood through an innate knowledge that transcends experience, ie, a metaphysics.
Our understanding of the world must always be limited
FH Bradley's regression argument illustrates the that relations have no ontological existence in the external world. The Binding Problem, that we experience a subjective whole rather than a set of disparate parts, illustrates that relations do have an ontological existence in the mind. As Kant argued that we make sense of the world by imposing our a priori knowledge onto our a posteriori observations in the external world, similarly we can also make sense of the world by imposing a reasoned relational logic onto a relation-free external world.
IE, both these show the inherent limits to our understanding of the world, in that we will only ever be able to understand those aspects of the world for which we have an a priori ability to understand. This means that there are things about the world that will forever be beyond our imagination, as a horse's understanding of the allegories in
The Old Man and the Sea will forever be beyond the horse's imagination.
Language is more than self-referential
As language is, taking one example, the observed a posteriori linkage between a name "red" and a known a priori part (red), rather than being said to be self-referential in the sense of the Coherence Theory of Language, language is still able to refer to the world in the sense of the Correspondence Theory of Language.
Summary
We know the world in two distinct ways - i) metaphysically, rationally, as an evolutionary memory, as a Sartrian existence, a Kantian a priori ii) physically, empirically, as a present experience, as a Sartrian essence and a Kantian a posteriori.