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Introduction to Logic
Introduction to Logic offers one of the most clear, interesting and accessible introductions to what has long been considered one of the most challenging subjects in philosophy. Harry Gensler engages students with the basics of logic through practical examples and important arguments both in the history of philosophy and from contemporary philosophy. Using simple and manageable methods for testing arguments, students are led step-by-step to master the complexities of logic.
The companion LogiCola instructional program and various teaching aids (including a teacher's manual) are available from the book's www.routledge.com/textbooks/gensler_l...
The companion LogiCola instructional program and various teaching aids (including a teacher's manual) are available from the book's www.routledge.com/textbooks/gensler_l...
416 pages, Paperback
First published December 13, 2001
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Displaying 1 - 16 of 16 reviews
April 27, 2014
Since this is a textbook, let's just do simple pros and cons.
PROS:
It's a fine introduction to symbolic logic and many different types of formal logical systems. Chapter 2 covers basic syllogistic logic, then it gets into more classical logic in chapters 6 through 9. Once you've learned about propositional and quantificational logic, it moves on to modal logic (10/11) , deontic/imperative logic (12), and belief logic (13). The way these build on each other and the way you learn in tiny bits is a great idea and quite effective in teaching the material. I am following his basic course through self-study and I've gone through Chapters 1,2,6,7, 8, and 10. I'm amazed at how easy it is and how much I've learned in a couple of weeks. I think I will persevere and go through the other symbolic logic chapters -- 9, 11-13 -- since it is easier to learn than I had thought.
What I especially like about its treatment of symbolic logic is how intuitive and mechanical the proofs are. The test for validity of syllogisms is a cinch to learn. Sometimes the translations are a bit difficult, but so far this is more like maths. Eventually you get a right answer, not just endless loops of intuitive guesswork and what not. This doesn't apply to everything (relational quantification logic), but it applies to most of the book. So it's more user-friendly than some of the other logic books I've looked at with the traditional proof methods and so on.
The Logicola program included with the book is also extremely helpful. I'd recommend that you use it for review - not only do you learn more, but it's like having a professor to consult in the absence of the real thing. You can get tailored logic problems at your level and immediate feedback on what you're doing wrong if you make a mistake.
Finally, the author is an incredibly nice man. I've e-mailed him on a couple of occasions and he has answered my questions.
CONS:
Its introduction to formal logic is too skimpy. The chapters about informal and inductive logic are also too short I think. What you really need are more thorough books for these two areas, and I think some other textbooks do a better job of introducing the subject as a whole.
Also, it's symbolic logic. This mostly seems to be formal systems of symbol manipulation with a lot of built in rules and assumptions. It may be usefully applied to extremely specific fields (computers, maths, and so on), but the main reason I'm working through this book is so I'm not completely at a loss if I encounter logical analysis in a book. Last month, for instance, I read a philosophical book on the Stoics with a heavy dose of logical analysis. Being completely dumbfounded by this, I selected this book to help me with my complete lack of logic ability.
On the whole, it's a fine book for learning basic symbolic logic. You should look elsewhere for learning inductive or informal logic -- 3.5 to 4 stars on my rating scale.
Be warned though: the Kindle version didn't translate too well from the paper version. There are mismatched problems all over the place and the formatting is often to blame for not being able to read some of the text. It's not a major problem, but it could annoy you in places.
PROS:
It's a fine introduction to symbolic logic and many different types of formal logical systems. Chapter 2 covers basic syllogistic logic, then it gets into more classical logic in chapters 6 through 9. Once you've learned about propositional and quantificational logic, it moves on to modal logic (10/11) , deontic/imperative logic (12), and belief logic (13). The way these build on each other and the way you learn in tiny bits is a great idea and quite effective in teaching the material. I am following his basic course through self-study and I've gone through Chapters 1,2,6,7, 8, and 10. I'm amazed at how easy it is and how much I've learned in a couple of weeks. I think I will persevere and go through the other symbolic logic chapters -- 9, 11-13 -- since it is easier to learn than I had thought.
What I especially like about its treatment of symbolic logic is how intuitive and mechanical the proofs are. The test for validity of syllogisms is a cinch to learn. Sometimes the translations are a bit difficult, but so far this is more like maths. Eventually you get a right answer, not just endless loops of intuitive guesswork and what not. This doesn't apply to everything (relational quantification logic), but it applies to most of the book. So it's more user-friendly than some of the other logic books I've looked at with the traditional proof methods and so on.
The Logicola program included with the book is also extremely helpful. I'd recommend that you use it for review - not only do you learn more, but it's like having a professor to consult in the absence of the real thing. You can get tailored logic problems at your level and immediate feedback on what you're doing wrong if you make a mistake.
Finally, the author is an incredibly nice man. I've e-mailed him on a couple of occasions and he has answered my questions.
CONS:
Its introduction to formal logic is too skimpy. The chapters about informal and inductive logic are also too short I think. What you really need are more thorough books for these two areas, and I think some other textbooks do a better job of introducing the subject as a whole.
Also, it's symbolic logic. This mostly seems to be formal systems of symbol manipulation with a lot of built in rules and assumptions. It may be usefully applied to extremely specific fields (computers, maths, and so on), but the main reason I'm working through this book is so I'm not completely at a loss if I encounter logical analysis in a book. Last month, for instance, I read a philosophical book on the Stoics with a heavy dose of logical analysis. Being completely dumbfounded by this, I selected this book to help me with my complete lack of logic ability.
On the whole, it's a fine book for learning basic symbolic logic. You should look elsewhere for learning inductive or informal logic -- 3.5 to 4 stars on my rating scale.
Be warned though: the Kindle version didn't translate too well from the paper version. There are mismatched problems all over the place and the formatting is often to blame for not being able to read some of the text. It's not a major problem, but it could annoy you in places.
September 17, 2012
Harry J. Gensler's Introduction to Logic is an overall introduction to basic logic(s). Overall a strong one with a noticable weak point. One of it's most firstly distinctive features is the downloadable software LogiCola, which turns out to be a very useful tool for revising, but be wary, writing down your exercises is important in properly digesting the material. Also, the examples and exercises from the book are much more interesting and philosophically inclined.
The explanations of proofs and refutations are just great. They are original methods which work great and saves the student from what otherwise could be a struggle and rely too much and intuition.
In order to complete this introduction adequately I purchased another book (The Language of Logic by Morton L. Schagrin) to help with translating quantificational Logic since I think Gensler's introduction is lacking in that department. Another insufficiency is that the context of a the logical systems isn't presented (until much later). Historical and conceptual contexts will help the process of understanding and make the whole process less mechanical.
Modal logic is a very welcome & unique addition as well as the lovely and vivid introductions to other subjects in later chapters (philosophy of logic, metalogic, Belief Logic to name a few).
Overall, strong on proofs and clarity but weak on translation and contextual richness.
The explanations of proofs and refutations are just great. They are original methods which work great and saves the student from what otherwise could be a struggle and rely too much and intuition.
In order to complete this introduction adequately I purchased another book (The Language of Logic by Morton L. Schagrin) to help with translating quantificational Logic since I think Gensler's introduction is lacking in that department. Another insufficiency is that the context of a the logical systems isn't presented (until much later). Historical and conceptual contexts will help the process of understanding and make the whole process less mechanical.
Modal logic is a very welcome & unique addition as well as the lovely and vivid introductions to other subjects in later chapters (philosophy of logic, metalogic, Belief Logic to name a few).
Overall, strong on proofs and clarity but weak on translation and contextual richness.
October 20, 2018
Great introduction to Logic. Textbook in our Philosophy of Logic class written by a Jesuit priest whose others books been also published in many languages. Some topics covered: deontic, relational, symbolic, imperative, belief, modal, quantificational, propositional and symbolic logic, among others. Download the logicola software program from his site: harryhiker.com to learn more. If you like math, this ones for you. Skip the beginning chapters if you want to do math-related logic right away.
January 6, 2010
Extremely helpful. I am no logician and though my field of study is very much conversant in and with philosophy both past and present, I found myself in need of a quick refresher of everything I had learned (and promptly forgotten) about Logic proper from my undergraduate studies.
Enter Gensler, who here does a fine job of succinctly and thoroughly providing no more and no less of what is needed. A concise logical argument should be able to be made, recognized, and supported after a reading of this book.
Two elements of the work are particularly valuable, I thought:
First, he builds on the material, so you need to be aware that you will be unable to "hunt and peck" within this text. Skipping around the chapters looking for points of interest if you are at all unfamiliar with or new to logic altogether will not be very valuable to you; you must start at the beginning and understand what is presented before moving on.
Second, there is an index of fallacies located at the back with what I think is a list of more helpful descriptions than are found in other sources (taking into account both printed and online sources), making it a valuable reference guide to have in your collection if this is something you may need to access in the future.
Enter Gensler, who here does a fine job of succinctly and thoroughly providing no more and no less of what is needed. A concise logical argument should be able to be made, recognized, and supported after a reading of this book.
Two elements of the work are particularly valuable, I thought:
First, he builds on the material, so you need to be aware that you will be unable to "hunt and peck" within this text. Skipping around the chapters looking for points of interest if you are at all unfamiliar with or new to logic altogether will not be very valuable to you; you must start at the beginning and understand what is presented before moving on.
Second, there is an index of fallacies located at the back with what I think is a list of more helpful descriptions than are found in other sources (taking into account both printed and online sources), making it a valuable reference guide to have in your collection if this is something you may need to access in the future.
December 4, 2014
Though this was a good book, I find that it is difficult to understand if one does not have access to the program that goes hand-in-hand with this book. It does not do well as a stand-alone, but is extremely helpful when it comes to understanding the Logic program. I found that when I was working with the program, I understood what the book was trying to tell me. This understanding did not happen without the program.
May 2, 2011
i only covered three chapters in this book, but the class was a nightmare! i cant understand it and its just been a terrible experience. i wouldn't wish this class, or book, on my worst enemy. So glad that the class is basically over.
December 2, 2014
Great text on logic. I would only recommend learning inference rules not documented herein from Copi or another text like that. Also, I never used the starring method he uses to augment proof writing. For those naive to formal logic, it's not strictly necessary.
August 20, 2019
Simply the most noob-friendly introductory textbook to logic. The accompanying practice program "LogiCola" is also highly recommended. Begin from here if you intend to learn logic.
May 2, 2023
Big ol book, and hard to read. But covers its ground pretty thoroughly. It gets an extra point for the invention of The Star Test in syllogistic logic. Crazy that developments as significant as that can be made in a discipline over 2,500 years old. Glad to be done with this one though
December 8, 2017
This is a textbook. Gensler is convoluted at times and that is a drag, but, this is a textbook.
February 4, 2023
Readable, easy to follow explanations and exercises about logic. A solid textbook on the subject.
January 18, 2023
The author, Prof Gensler, is an incredibly nice person who patiently replied my email which asked a very very stupid logic question, about a year ago. Now I look back at my naive question and can’t help being touched by his amazing friendliness and patience. As for the book, I would commend it for its clarity and approachability, as my beginner’s guide to formal logic and methods of reasoning. It starts from the basic rules of logic and symbols, step-by-step leading to the deeper and advanced quantificational logic, modal logic, deontic logic and even metalogic, which will be very helpful for those interested in analytic philosophy and mathematical logic. Overall it is a good journey, though it can be difficult sometimes to digest.
A reminder that sometimes people use different symbols for logic. For example sometimes the ‘if…then…’ symbol is written as an arrow, sometimes as a horseshoe; the ‘negation’ is sometimes written as ~ while sometimes as a wedge. In this book the horseshoe and the ~ are used, which is slightly different from the standard of some universities.
A reminder that sometimes people use different symbols for logic. For example sometimes the ‘if…then…’ symbol is written as an arrow, sometimes as a horseshoe; the ‘negation’ is sometimes written as ~ while sometimes as a wedge. In this book the horseshoe and the ~ are used, which is slightly different from the standard of some universities.
November 17, 2014
Harry J. Gensler's "Introduction to Logic" is by far one of the best books about elementary logic that i have encountered. All the basic rules such as the rules of inference, introduction rules, elimination rules, etc, are explained with out most simplicity and clarity. Another great fact about this book is that it devotes chapters on the history of logic and the philosophy of logic unlike other logic books wherien these information are cluttered and spread throughout different chapters. Finally i appreciated that the author gives a complete answer key to his review questions
April 16, 2014
مدخل جيد جدا لدراسة المنطق بالانجليزيه (للأسف لم اجد حتى الآن مثيل له بالعربية)
لغة الكاتب سهله وبسيطه و صياغاته ابعد ما تكون عن التعقيد
التمارين في نهاية كل فصل ذات فائده كبيره لفهم موضوعات الكتاب
بالاضافه لبرنامج التمارين "لوجيكولا" الممتع والذي افادني كثيرا لمراجعه فصول الكتاب مراجعه سريعه كلما اردت.
البرنامج متاح مجانا على موقع المؤلف
رابط التحميل بالاسفل
http://www.harryhiker.com/lc/index.htm
لغة الكاتب سهله وبسيطه و صياغاته ابعد ما تكون عن التعقيد
التمارين في نهاية كل فصل ذات فائده كبيره لفهم موضوعات الكتاب
بالاضافه لبرنامج التمارين "لوجيكولا" الممتع والذي افادني كثيرا لمراجعه فصول الكتاب مراجعه سريعه كلما اردت.
البرنامج متاح مجانا على موقع المؤلف
رابط التحميل بالاسفل
http://www.harryhiker.com/lc/index.htm
August 6, 2013
This was a good and enjoyable book for me as an introduction to logic as it wasn't too heavy-going. Overall I recommend it as one of the first books to read on the subject as it's more accessible.
November 10, 2015
The most comprehensive guide to logic I have ever read. It explains the reasoning behind the theory as opposed to just showing you how to solve the problems.
Displaying 1 - 16 of 16 reviews