Ernst Cassirer never formulated a poetics of art and/or literature. His principal significance to literary theory is his conceptualization of irreducible cultural forms, including not only art/literature but also mythology (covalent with religion), science and philosophy. Cassirer's conception is fundamentally pluralistic, in that no form subsumes any other, in contradistinction with the way a figure such as Sigmund Freud viewed both art and mythology as extensions of his (alleged) scientific paradigm.
Now when conceptualizing the above forms, particularly "myth," Cassirer focused almost exclusively upon the evolution of archaic mythico-religious systems. He seems to have been aware that some thinkers believed that myth survived into his contemporary times in one guise or another, but in his writings on art he did not strongly expouse myth as a principle overlapping with literature, as was the case with Northrop Frye, the best-known proponent of "myth criticism" as well as a critic strongly influenced by Cassirer in other ways. Cassirer's work explored the ways in which archaic cultures, dominated by mythico-religious systems, gave birth to the discursive theoretical forms of science and philosophy. Thus whenever Cassirer speaks of myth, as in his book MYTHICAL THOUGHT, he primarily refers to the state of myth in archaic human societies, prior to the rise of the theoretical forms.
Nevertheless, some of Cassirer's formulations certainly influenced Frye. I've mentioned in other essays Frye's conception of literature as a spectrum with naturalistic "verisimilitude" at one extreme and what Frye termed "myth" at the other-- by which, of course, Frye did mean a form of myth-like complexity present in formal literature. This parallels Cassirer's opposition between the world of causality, over which science comes to hold dominion, and the world of internal expressivity, which is first communicated among humans through myth and mythic rituals. Indeed, though "intersubjectivity" as a term does not appear in Cassirer, his analysis of archaic myth makes clear that it can be easily regarded as mankind's first attempt at intersubjective communication.
In MYTHICAL THOUGHT Cassirer defines causality as "the general concept of force" (p. 14). Cassirer knew that primitive peoples were as aware of causal forces as was Isaac Newton; otherwise, they could hardly have constructed those objects that take advantage of Newtonian forces, such as clubs and boats and pyramids. However, in addition to their awareness of such forces, Cassirer asserts that primitives also believed in what I would term an "acausal force," though Cassirer's term is "magical efficacy."
"Magical efficacy" almost certainly traces from the "mana" theory of Robert Codrington's book THE MELANESIANS (1891), to which Cassirer refers in other works. However, in keeping with Cassirer's post-Kantian project, he's concerned with the application of this "efficacy" as a prelude to religion:
"More and more clearly we see the beginnings of a mythological view which assumes a distinct concept, neither of God nor of the psyche and personality, but starts from a still entirely undifferentiated intuition of magical efficacy, of a magical force inherent in things." (p. 16)
This force approaches ontology from a different perspective than that of commonplace causal reality, in part because space itself is transformed by internal sensation:
"For myth all difference of spatial aspect involutarily changes into a difference of expressive features, of physiognomic characters. Thus [myth's] spatial view, in spite of its tendencies toward objective formation, remain bathed in the color of feeling and subjective sensation" (p. 152).
Given that myth "appears closely bound up with the world of efficacy," the two of them together comprise "a translation and transposition of the world of subjective emotions and drives into a sensuous, objective existence."
To be sure, Cassirer does not emphasize that this objectivity is dependent upon its transmission through culture, in contradistiction to scientific law, which science assumes to be true independent of any human opinion on the subject. But in my view it's only a short step from Cassirer's "expressive features" and "physiognomic characters" to the archetypes of Jung, which, as past essays have demonstrated, provide clues to a phenomenology capable of putting both causal and mythical worlds into their proper perspective.
And in the conclusion to the METAGODZILLA series, I'll go into more detail as to how the antithesis of the causal and the intersubjective throws light on the valuation of different literary phenomenalities.