What you are terming “structural fallibilism” seems to me possibly a way to get at one technical difficulty in trying to apply Peirce’s outlook, though I’m wondering whether more is required. Fallibilism of any kind is about the status of what one knows, but is what one knows or does not know a broad enough outlook? Is what one senses, but may not yet know, or even ever know, another modality than the rightness of what one knows?
Fallibilism is requisite for theoretical life, for science, for Peirce. But he also sees the ability to act from belief as requisite for practical life, and argued theory should not intervene in practice, because it is too “thin” for the practice of life. Similarly, belief has no place in science, which must limit itself to opinion, i.e., fallible opinion. The essence of science for Peirce, who, remember, was the founder of pragmatism, is that it is useless.

Peirce himself was a scientific radical and a political conservative. He described himself as a sentimentalist in practical affairs, also noting how the term sentimentalist had taken on a pejorative sense since the Enlightenment. Yet sentiment is for Peirce the percolating up of deeper, tempered capacities of the human creature to inform practical conduct in a full-bodied way that critical thought could not. A “gut” reaction may be a better, more prudent response to a vital crisis than a….(with all due apologies to Deliberately Considered)……deliberately considered…..one, especially if quick, decisive action is needed.

Peirce: “If I allow the supremacy of sentiment in human affairs, I do so at the dictation of reason itself; and equally at the dictation of sentiment, in theoretical matters I refuse to allow sentiment any weight whatever…We believe the proposition we are ready to act upon. Full belief is willingness to act upon the proposition in vital crises, opinion is willingness to act upon it in relatively insignificant affairs. But pure science has nothing at all to do with action. The propositions it accepts, it merely writes in the list of premises it proposes to use…” (Collected Papers 1.635).

So from this perspective, do you think your idea of structural fallibilism goes deeply enough in Peirce’s sense? Or might you see it as a corrective to Peirce’s sentimentalism?

Eugene Halton