Concerning the so-called empty names
pp. 126-130
in: Jerzy Pelc (ed), Semiotics in Poland 1984–1969, Berlin, Springer, 1979Abstract
The traditional dichotomous division of names into general and singular has been replaced in contemporary logic by a trichotomous division: general, singular, and empty. As Professor Kotarbiéski says in Gnosiology, "There are singular terms, which denote one and only one object, there are general terms, which denote more than one object, and there are empty terms, which denote no objects at all".1 We usually find cited as examples of empty names such self-contradictory names as 'square circle" or 'son of a childless mother", or names of mythical deities — fictitious figures that exist only in legends, poems, novels, etc. The singling out of empty names is important in the structure of logical calculus, and especially that part of it which the handbooks of logic term traditional logic. This logic, granted the traditional interpretation of propositions in the square of opposition, proves in tota valid only with regard to those propositions which do not include empty names.