ABSTRACT
In the previous chapters you’ve explored a sample of logical theories. All of the theories so far discussed are in broad agreement not only on the set of logical expressions (i.e., on what should be counted among our logical expressions), but also roughly on how they should be treated-on what the truth-ina-case conditions are for the given expressions. (The differences among the theories discussed so far are largely differences on what sort of cases should be acknowledged, but not on how truth-in-acase is to be defined for the various expressions.)
There are many more logical theories than mentioned-let alone discussed-in this book. One route towards difference involves recognizing more (or, for that matter, fewer) connectives than we have so far discussed. Another route towards difference retains the same set of logical expressions but, for various philosophical (or other) reasons, treats the logical expressions-that is, their truth (or truth-in-a-case) conditions-differently.
