Modal Logic for Philosophers

The method of this book is intuitive and thanks to all the exercises you won't miss a point.I definetely recommend this to all interested in modal logic.I've worked throught it during a course at university.

Let me begin by saying that this is one of the best introduction to modal logic and its mechanisms I have seen. So I will unhesitatingly give it five stars. But the rest of my review will be a bone I have to pick with the title of the book. This is not a book of modal logic for philosophers. It is a book of modal logic for mathematicians. When I purchased the book, I thought it was going to be about how modal logic is used to solve philosophical problems. What it is is a book about how to do modal logic.There are three levels involved with modal logic. The first is syntax -- rules about how to operate the squiggles on the page to obtain other squiggles. The second is semantics -- what the syntactical rules are named and how the rules are to be applied. "Semantics" does not mean quite what it means in ordinary discourse, be warned. It does not mean "extracting meaning from the syntax." That is the third level -- interpretation. On that level, the squiggles -- squares, diamonds, connectives, etc. -- can be used to mean many different things. To give an example, the "necessarily" squiggle -- usually represented by a square, sometimes the letter "L," can mean logical necessity, practical necessity, scientific necessity, ordinary language necessity, or a number of other things. Which meaning of necessity we choose determines whether a given system of modal logic is useful. For some interpretations, even the weakest of systems is of dubious value. For instance, consider the ordinary language use of probability and necessity-type language. Lawyer: "Could George have done it?" Witness: "No, he couldn't have done it." Lawyer: "But is it possible that he could have done it?" Witness: "Anything's possible." Even the almost universal modal rule that "Possibly P is equivalent to Not Necessarily Not P" can't do much with this common kind of colloquy. On the other hand, if "necessarily" refers to logical necessity, modal logic is almost useless, because everything that is not a contradiction is logically possible, and I do not believe a modal proposition can be contradictory unless that proposition, stripped of its modal indicators, does not present a contradiction in the propositional calculus (I may be wrong about this, though. A counterexample from a reader would be welcome). And if "necessity" is interpreted as "logical necessity," then a statement like "Necessarily, a baseball game cannot end in a score of 2,000,000 to 1" is false.What a really wanted from this book was examples and story problems indicating the use of various systems of modal logic under various interpretations of its propositions and connectives. I wanted a exploration of "possible worlds" applications. Philosophers conversant with modal logic regularly say that conceiving of modal propositions in terms of possible worlds helps to solve many knotty problems when dealing with counterfactual statements. How or why does it do so? Give some examples. And I wanted some discussion of what various interpretations of possible worlds would be. Possible worlds semantics can lead to some wild claims, like David Lewis' suggestion that all possible worlds really exist somewhere out there, but we can't access them. Huh? Worlds with talking donkeys and 2,000,000 -- 1 baseball games? What we want is a set of possible worlds that represent real possibilities. Discussion of they are, please.I don't mean to be so critical of what is a fine book, and just happens not to be what I was looking for. If you want a good introductory overview of what modal logic is and how to do it, this is your book. If you want to know what to do with it once you've mastered its intricacies, it is not.

I taught standard propositional and predicate logic for many years, and soon realized what they couldn't do. I knew I had to know something about Modal Logic in order to more fully understand how reasoning works in real life. This book is the best introduction to the subject I have seen. It is clear and straightforward, and the exercises really make the concepts part of your daily thinking. Fascinating stuff. Highly recommended

Great book. Though some might consider this more 'mathematical' than necessary for philosophers, it is definitely written for philosophers. Anyone who has done well in a proof based math class will find it a bit hand-holdy in it's explanations of proof strategies. That said, it will be thoroughly informative for anyone interested in learning modal logic, mathematician or philosopher. Full disclosure, I haven't yet completed the book. I will update my review if I come across anything odd.

Some formulas can't render on any platform whatsoever.