With the rise of Materialism and Physicalism a dualistic ontology has fallen out of favor. The successes of Science makes makes us comfortable to deny any entity beyond the "Observable Universe". Humanity has fallen into the habit of saying: "Science has all the answers, or will get them soon".
Duality itself is mostly thought of as a world of opposites, like a static interpretation of Yin Yang, or simply as existential incommensurables. The view is that Duality is one part real and one part unseen, unscientific, imaginary things. However looking closer we find a multitude of dualities, some discredited ontologies, some abstract concepts, mathematical realities and scientific facts. Moreover there are different modes of "opposition", co-dependence, or perspective paradigms.
Then there are the following:
In Formal Logic we learn that the Form of the argument is paramount, not the truth value of it's statements. We have to have a valid argument before we can have a sound argument. But then, in order to go from a valid to a sound argument we need to introduce something from outside it's form: we need to assign truth values. Thus for rational reasoning itself we have a dual aspect, we have to draw on two domain ontologies: one from the study of Logic and one from the study of (for instance) Science. https://en.wikipedia.org/wiki/Argument
Predicate dualism, as used by Donald Davidson in his thesis of Anomalous Monism https://en.wikipedia.org/wiki/Anomalous_monism & https://en.wikipedia.org/wiki/Mind%E2%80%93body_dualism#Predicate_dualism, tells us that "mental events are identical with physical events, and that the mental is anomalous, i.e. under their mental descriptions, relationships between these mental events are not describable by strict physical laws". It is some of the predicates we use that cannot be described by physical laws, but that they are a necessary abstraction for cognitive processes. Now to me this sounds like a consummate monist has implicitly stated that there are a dual nature to the human being: a physical gestalt and a mental. Can the Mind even exist without a dualistic, or multiplistic, construction.
Moreover from Information Science ontology, https://en.wikipedia.org/wiki/Ontology_(information_science) we learn that not all ontologies are compatible. Ontology alignment is a manual process, i.e. a top down operation that requires the intervention of an entity(programmer) with more information/knowledge than is contained in either or both the ontologies to be merged. Not only an understanding of the contents of each, but also an understanding of how they relate, is required. Considering this taken with the implications of Predicate dualism, we should begin to wonder, with renewed vigor, how the physical process of Evolution could produce the Human Mind.
Also of interest, some examples of physical processes or the theories used to describe them:
Implicate and explicate order from David Bohm's book: Wholeness and the Implicate Order.
Wave–particle duality: https://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality
Now from all this it seems that certain phenomena cannot be comprehensively described by a single ontological paradigm or a cohesive theoretical framework. Maybe because of pragmatic/efficient reasons, maybe it is a physical effect of Gödel incompleteness... At the end of it all Duality, in all of it's guises, permeates every one of our intellectual endeavours. Might one even say that Duality may be more than a second ontological category but even a fundamental principal of our familiar material ontology.
Is there any efforts towards incorporating a view such as this into a rigorous theory of existence? Has Dualism been completely abandoned? Is there any account for why dualistic phenomena are so commonplace? (apart from simple denial or an appeal to incomplete information)
There are forces that attract, and there are forces that distract.