ABSTRACT
In the last chapter, we recognized ‘atomic innards’ by adding a set of predicates and names. In turn, we expanded our cases to cover predicates and names. Unlike the last chapter, this chapter adds a new logical expression (viz., an identity predicate), and in turn offers truth (and falsity) conditions for the new expression. (This is done by imposing constraints on our cases.)
8.1 Logical expressions and logical form
In Chapter 2, we noted that logicians tend to think of validity as a matter of logical form. So far, we have treated logical form as a matter of logical connectives: we specify different logical forms of sentences in terms of the logical connectives in our language. Moreover, we have so far recognized only (let us say) ‘basic forms’, forms defined out of (what we have called) basic connectives: conjunctions, disjunctions, and negations.1 All of these basic connectives are sentential connectives: syntactically, they take sentences and make new sentences.
