Abstract

Ordinarily, in mathematical and scientific practice, the notion of a “theory” is understood as follows: (SCT) Standard Conception of Theories : A theory T is a collection of statements, propositions, conjectures, etc. A theory claims that things are thus and so. The theory may be true, and may be false. A theory T is true if things are as T says they are, and T is false if things are not as T says they are. One can make this Aristotelian explanation more precise, as Tarski showed, in the cases where we understand how to give precise logical analyses of theories, by identifying an interpreted language L, Á) in which T may be formulated. Here L is some formalized language and Á is an L-interpretation. One can define the satisfaction relation ⊨, holding between L-sentences j and L-interpretations, and then define the notion L-sentence j is true in L, Á)” as Á ⊨ j”. What is essential about this is that theories are truth bearers . They are bearers of semantic properties.