Peirce's categories (technical name: the cenopythagorean categories)^[8]

Name	Typical characterizaton	As universe of experience	As quantity	Technical definition	Valence, "adicity"
Firstness[9]	Quality of feeling	Ideas, chance, possibility	Vagueness, "some"	Reference to a ground (a ground is a pure abstraction of a quality)[10]	Essentially monadic (the quale, in the sense of the such,[11] which has the quality)
Secondness[12]	Reaction, resistance, (dyadic) relation	Brute facts, actuality	Singularity, discreteness, "this"	Reference to a correlate (by its relate)	Essentially dyadic (the relate and the correlate)
Thirdness[13]	Representation, mediation	Habits, laws, necessity	Generality, continuity, "all"	Reference to an interpretant*	Essentially triadic (sign, object, interpretant*)