Firstness (the thing in itself), Secondness (resisting), and thirdness (inter-; intermittent);
In other words – qualitative immediacy, brutal confrontation, and dynamic mediation.
Peirce‘s categories are designed to draw attention to what he believes are always available aspects or features of each phenomenon.
Everything that is before reason is somehow inexpressible (the unique in itself cannot be communicated), it stands out (everything that is before reason is also opposed to reason. It emphasizes itself as opposed to others) and is understandable (it can be noticed by name and even to some extent interpreted and explained).
Charles S. Peirce’s categories of firstness, secondness, and thirdness are at the same time the most important (because they show in-depth and guide his research on signs) and the most difficult side of his ideas.
One of the functions of the Peirce categories is to lead and stimulate inquiry. In short, they are heuristic. This is evident from the way Peirce uses categories in the many characters he studies. Each sign can be taken as something in itself, it could also be considered in relation to something else (its object), finally, the sign can function as something between the two (the factor mediating the object and the interpretant).
From this trinity scheme, Peirce created three trichotomies; the first – qualisign, sinsign, and legisign; the second – iconic sign, indexical sign, symbol; and the third – rheme, dicent, argument
