6.3 Semantics, Syntax and Pragmatics
You've been using BOOL to translate sentences from English and to construct truth tables. In this section we step back and reflect on what we are doing and why.
A logical system has several parts: first, you learned the symbols and grammatical rules for making sentences in BOOL; second, you learned how truth works in BOOL: the truth or falsity of complex sentences depends just on the truth or falsity of simpler sentences.
BOOL is not that different from a natural language like English. English also has grammatical rules. And even though not all connectives in English are truth functional, many are.
A distinction from linguistics and philosophy of language can help us understand these parts of BOOL: the distinction between semantics, syntax, and pragmatics.
Syntax = grammar.
Pragmatics = use.
Basically, semantics includes concepts like meaning and truth; syntax includes concepts like grammar and form; and pragmatics refers to how words can be used in different ways in different contexts.
Let's see if you can apply the concepts to BOOL.
The logical systems we create will have several semantic and syntactic features, so as you learn more about BOOL, you should ask yourself: is this part of BOOL's semantics or syntax?
It is helpful to understand what pragmatics is, but we will not develop a pragmatics for BOOL. Pragmatics concerns features of language when it is used in specific circumstances, like when someone utters in a courtroom "Pia is guilty."
That utterance, even though it has a set meaning and grammar, can still have different significance depending on whether it was said by the prosecutor, trying to convince the jury, or by the judge, when sentencing Pia.
Those are pragmatic considerations.
We will use BOOL to study how we reason, but we won't actually start talking in BOOL, so we won't focus on pragmatics in this book.