DEFINING BASIC KINDS OF PROPERTIES

Abstract: This paper follows in Pavel Tichý’s concept of distinguishing between trivial (i.e. constant) and nontrivial properties. This classification has been extended by Pavel Cmorej who distinguished two kinds of nontrivial properties, namely purely empirical and partly essential (which are partly empirical) properties (partly essential property is essential for certain individual(s), but that it is not for other(s)). The present study provides rigorous formal definitions of trivial / non-trivial, essential / non-essential, and purely empirical / partly essential / purely essential properties with respect to the possible partiality of these properties. In addition, a definition of trivially void properties completing the classification of the kinds of properties to form a quadruplet is proposed. Furthermore, the introduction of the concept of accidental properties gives rise to another (yet not equivalent) quadruplet: purely accidental / partly essential (i.e. partly accidental) / purely essential / void properties. Pavel Tichý, a logician who developed a specific intensional logic, namely transparent intensional logic (hereafter TIL), used his logic not only for a logico-semantic analysis of natural language but he also applied it to problems in several philosophical areas. The field we are concerned with in this paper can be called ‘the logic of properties’. Intensional logic may be viewed as a conceptual tool helping to develop intensional metaphysics. According to its main assumption, an individual can instantiate various properties. Properties are modelle