ABSTRACT
Logic is about consequences. Take a body of propositions. The job of a logic is to tell you what follows from that body of propositions. Sometimes we are interested in consequence relations on propositions "in general." That is, we pay no attention to the subject matter of the propositions, we pay attention only to the logical relationships between them. This is the traditional scope of philosophicallogic. But logic is pursued in other ways too. Sometimes we are interested in particular sorts of propositions - those which have to do with particular structures. We might be reasoning about times or places or processes or some other kind of structure. Logic can be particular. This multiplicity of interests affects the state of logic as a discipline. Logic has a home in philosophy because it studies reasoning with propositions in their generality. But the techniques used in philosophical logic can be fruitfully brought to bear on particular problems, for reasoning about particular structures. This is what makes formal logic useful in computer science (we can reason about processes, functions or actions), theoretical linguistics (we can reason about grammatical structures), mathematics (we can reason about mathematical structures), and other fields.
