ON THE INTERACTION OF SEMANTICS AND DEDUCTION IN TRANSPARENT INTENSIONAL LOGIC (IS TICHY'S LOGIC A LOGIC?)

It is sometimes objected that Tichy's logic is not a logic because it underestimates deduction, providing only logical analyses of expressions. I argue that this opinion is wrong. First of all, to detect valid arguments, which are formulated in a language, there needs to be logical analysis to ascertain which semantical entities (Tichy's so-called constructions) are in volved. Entailment is defined as an extralinguistic affair relating those con structions. The validity of an argument, composed of propositional con structions, stems from the properties of the constructions. Such properties are displayed by the derivation rules of Tichy's system of deduction.