It seems to me that the form of the question has been for a long time: how does one put mind and matter, as given to us, into a single frame? And there is a growing realization that this is not only impossible, but not even intelligible when thought through. One can trace the beginnings of this realization to Spinoza and Kant, and attempted solutions often took the form of "overcoming" the subject-object divide. We can certainly have a unified third person perspective on both mind and matter, and a useful one at that, but the mind can not appear in it as a first person given, by definition. Similarly, we can have an experiential, "mindful" perspective on matter as reaction, resistance, external qualia, but that does not present it as the realm of causal relations, a perspective that gives science its power. As Nagel puts it in What is It Like to be a Bat?:
"Some may think there is nothing to prevent mental phenomena from eventually being recognized as physical in their own right. But whatever else may be said of the physical, it has to be objective. So if our idea of the physical ever expands to include mental phenomena, it will have to assign them an objective character — whether or not this is done by analyzing them in terms of other phenomena already regarded as physical. It seems to me more likely, however, that mental-physical relations will eventually be expressed in a theory whose fundamental terms cannot be placed clearly in either category."
Attempts to find such mediating concepts that combine discrimination and action, observation and volition (like "skill", "habit" etc.) have been made, but we are a long way off from a synthesis. And for them to succeed "mind" and "matter" will have to be reconstructed from a more remote fundamental perspective, which is no easier than formulating quantum gravity. Many intractable debates in the modern philosophy of mind come from asking for a unified perspective... that still has "mind" and/or "matter" as fundamentals. This is no more promising than quantum gravity in classical spacetime.
The "problem" of the unconscious comes from such crude mixing of the two perspectives. Hartmann's Philosophy of the Unconscious was roundly dismissed as incoherent for attempting just that, and not only by idealists. Interpretivists, like Dilthey, understood the "subconscious" as dimly conscious that can be brought forth with training and effort. In fact, Dilthey suggested a programme of developing first person psychology, and human sciences in general, based on such ideas, which was picked up by Jaspers, Spranger, and others under the name of understanding-psychology or humanistic psychology, see Teo's Critique of Psychology. But if the first person meaning of "conscious" is taken as meaning-giving, then an "unconscious process" is nonsensical. However, this is not how Freud and others interpret the "unconscious processes". To them they are theoretical entities "needed to explain various psychic facts that escape consciousness: principally dreams, symptoms, slips of the tongue, and jokes", i.e. to fill in empirical causal gaps, see How do psychoanalysts like Freud and Lacan interpret the concept of "proof"? And this is perfectly legitimate, as are physical models of conscious action in neuroscience, as long as we do not expect the "what-it-is-likeness" of consciousness to jump out of them.
Zhok in Phenomenological Reading of Anomalous Monism comments on Husserl's explanation of why a one-view (from nowhere?) mixing of causal and experiential aspects is hopeless, and likens it to Davidson's, in his anomalous materialism:
"Once efficient causation is constituted, we can successfully apply its descriptive model to manifold explanations, but the only explanatory act that is a priori forbidden is the conceptual reduction of agency and subjectivity to efficient causality, because the constitution of efficient causality presupposes the efficacy of ‘agent causation’. Now we are in a position to fully understand why, as Husserl put it, “Motivation als eine Art Kausalität ansehen (…) ist widersinnig” [Identifying motivation as a kind of causality is nonsensical]. And it should become equally clear why mental events cannot be reduced in any sense to physical events, even if we accept a monistic ontological framework".
