Introduction to Logic

I've never had an easier, yet more rigorous, introduction to logic. From the start, the author engages you in interesting explanations which are very clear. The Logicola software is great as well, which without, I would not have understood the material as good as I do now. It's only been 4 days and I'm already on chapter 4, having done EVERY problem in the book so far and many on the software! For self study, there is no better.

I agree with the other reviewers of this text that it is the best I've encountered (I have taught several different sections of logic over nearly ten years, using 6 or 7 different texts, and have reviewed countless others). The writing is admirably clear and precise, and reads well. Nothing extraneous here, but there is enough to elucidate ideas and strategies. There are two key features that distinguish this text from others, and render it extremely valuable. (1) the examples and logic problems are INTERESTING, mostly because they are invariably drawn from philosophical arguments; this gives me an opportunity to tie the teaching of logic to discussion of philosophy and makes the relevance of logic to philosophy very clear; I often find students who are interested in philosophy because they have read existentialism or even Plato, and who appreciate the play of ideas they find in these texts; what they do not understand is that the poetry of ideas must be tied to logic, and, more importantly, that there is a kind of poetic rigor to logic; this text helps to make that clear. (2) Gensler has developed a remarkably simple set of strategies for proof construction, that eliminates much of the confusion and ambiguity that students experience when encountering proofs for the first time; his "star test" for testing syllogisms is excellent, and a cinch to apply; it is even easier to grasp than Venn diagrams and is more versatile; his strategy for proofs in propositional and predicate logic is the best and easiest I've seen anywhere, and combines the merits of truth trees with standard deductive proofs, and has the advantage of yielding both proofs of validity and refutations by the very same method. The ease of the strategy means that it is possible to move much further in a single semester than usual. The content of the book goes further, too, than many of the standard textbooks. He goes into modal logic, belief logic, deontic logic and even has a chapter presenting a formalized ethical theory. Very cool stuff!! (3) The only weakness I have found is in his explanation of translations; where he is very helpful and precise with strategies for producing proofs and refutations, his guidelines for producing translations into formal symbolism are a bit more vague and amount to only a few guidelines and a bit of hand waving. Still, even here I haven't seen much better elsewhere, so this is a minor quibble. In the context of my classroom, it just meant that this was something we spent more time on. I really can't recommend this book highly enough for those who are interested in logic.

This is the best introductory book on symbolic logic I have seen. It covers not only propositional and predicate logic, but also modal, deontic, and inductive (probabilistic) logic, and it does so with remarkable clarity and economy. Professor Gensler's proof method differs slightly from those in most textbooks, but I find it more intuitive and therefore more useful. His examples are drawn from everyday life and from arguments of the great philosophers. His exercises are well designed, too. And at one-third the cost of most other (and much inferior) textbooks, this book is a great bargain. I am not sure what the previous reviewer was referring to in his complaint about the lack of an index. This edition contains an index to proper names, while the excellent glossary of logic terms also functions as an index by listing the section numbers where each term is defined and discussed.

Gensler's approach is simple, witty, clear, and user-friedly. He doesn't pack in so much information in each chapter that the students get bogged down with surfeit info. The exerceises are good ones (and I've seen many books that have bad ones); Gensler provides a teacher's manual FREE online, as well as helpful hints on how to organize the course over a semester or year; the Logicola program is free!! and it's the best out there: it gives immediate feedback to the students; it is super easy to grade and track the students' progress. The book is also inexpensive relative to others (hurley's is about $90). Use this book, you will NOT be sorry!!!

I have taught logic for 31 years in colleges and universities. This book, along with its logicola software prgram downloaded for free from the net, has allowed my students to learn more logic in a semester than any of the other standard books that I have ever used. I used an earlier edition of this book in 1989 and was sorry to see it go out of print. When it came back, I quickly ordered it. My students love it and the logicola program. If you want to know logic and cannot take a course, but have the will, get this book, download the logicola program, and get to work. You will not be sorry!!! Just a tremendous value and an excellent text book that covers enough material for two or even three courses in logic!!! Best wishes!