Monday, April 19, 2010

Bleg: Online logic materials?

An ISW reader facing an unexpected teaching challenge asks for your help and guidance:

"I've been hired to teach a course titled "Logic" at a small university.

I'll be teaching two courses beginning in less than a month. Today I finally was able to get a look at the textbook (already ordered by them for the course) and some example syllabuses from past instances of the course.

It turns out it will be almost impossible for me to use these syllabuses and this textbook in good conscience. The book simply _isn't_ a logic book. It's more like an Intro to Philosophy textbook, and (I won't name the text but) it's not even a very good book for _that_ purpose. The syllabuses, similarly, do nothing to teach actual logic and focus on writing position papers on various philosophical and personal/religious/political issues.

One option, of course, is simply to pretend it's not a logic class and teach it as an intro course instead. But I was told when I was hired that one reason they were looking for someone to teach these courses was so that they would have someone teaching Logic, Critical Thinking and Philosophy courses who actually _knows_ logic, critical thinking and philosophy in some professional capacity. As such, it seems it is part of my _duty_ (not just my own personal inclination) to correct the curriculum here. Moreover, I suspect that accreditation probably turns in part on whether students in critical thinking and logic classes (core classes) are actually being taught something _about_ logic and critical thinking. So I think it's best for the university itself if I make this adjustment to the curriculum. Also, I think logic is valuable, and that I'd be doing a disservice to my _students_ if I didn't teach it to them.

So. Problem. I have this course to teach in less than a month, and I have no text, and perhaps even more importantly, I have no exercises to give the students to let them have practice with the concepts I'd be teaching.

The first round of courses I'm going to teach are compressed. There are only eight three hour meetings, each meeting intended to cover _two normal weeks_ worth of material. Clearly most of the value is going to come from the students working at home on exercises and getting feedback on them.

My current plan is not to run it simply as a Propositional Logic course. I'm going to take a broader approach. It won't be a mere critical thinking course (the students are supposed to have already taken one of those before they take this course) but will take a more in-depth look at the notion of formalized reasoning. The students will be constructing and analyzing actual argument rather than just manipulating formal symbols, but they'll be demonstrating in these constructions and analyses real understanding of the role and value of formalized techniques for dealing with arguments. It's kind of like an applied logic class. (Not just critical thinking, but actual logic, but not just logic, rather, applied logic.)

So here's what I need, and what I haven't been able to find, and which I hope you might be able to help me find by publicizing (anonymously please!) my plight at the blog In Socrates' Wake. I need good exercises designed to help teach the following concepts:

Logical vocabulary (such as validity, soundness, inductive, deductive, inductive strength, argument form, premise, conclusion, etc.)
The formalization of and evaluation of:
--Inductive Generalizations
--Causal Argumentss
--Arguments by Analogy
--(Possibly Abductive arguments, though I haven't thought this one through yet and I'm not sure I'll include such a section in the final course)
--Arguments best formalized in propositional logic (I won't be having the students deal with particularly complicated proofs here)
--Arguments best formalized in categorical logic

My plan right now is for assessment to be through their performance on worksheets and quizzes, as well as very short logical analyses (in English prose) of arguments found "in the wild" so to speak, together with performance on one or two "position papers" in which they're expected to show facility with logical vocabulary and the forms of argument mentioned in the list above.

Some may wonder what I mean by "formalizing" inductive types of arguments like Inductive Generalization and so on. I just mean the notion of abstracting from a specific argument to those characteristics just relevant to evaluating its strength. (That's a description that applies to deductive logic as well of course!) So for example, for an inductive generalization, you'd extract a population, sample, target characteristic, sampling method, and so on. That's what I'd call a "formalization" of an inductive generalization. The big idea of the course is learning how to think through arguments of varying levels of difficulty by learning how to consider them formally, as instances of this or that type of argument, whether they be deductive or inductive.

What I'm _hoping_ for is that there are sets of exercises like this to be found online somewhere that I simply haven't been able to discover. Or that some kind reader of your blog has access to some such sets of exercises in an electronic format that they'd be able to forward to me. Or any other fortunate outcome.

Really, really awesome would be if someone knows of an open-content Logic (or even the right Critical Thinking) textbook online that covers the above topics or roughly the above topics.

Thanks for any advice or help!"



  1. My colleague P. D. Magnus has an excellent logic textbook online for free: *For All x* at

  2. I remember I used Trudy Govier's A Practical Study of Argument when I was taking my Critical Thinking Class. It was not so bad.

    We started understanding what arguments are, how to diagram them, etc. and towards the end of the course learned a bit of propositional logic (via long and short truth-tables).

    Plenty of exercises.

    Hope that helps.

  3. off topic suggestion: I'd like to see a ISW post on possible new tech tools for use in philosophy teaching.

    My university has a fund for such expenses. I've heard of a few people using clickers to do in class polls on cases. Apart from that I'm not sure what tools that are useful and available. Maybe you all can make some suggestions?

  4. Here's something that doesn't seem to fit what you are looking for (but maybe you'll change your mind); Paul Teller's logic books:

    And perhaps Richard Feldman's "Reason and Argument" notes could help out too; this is a really excellent book that seems to perfectly fit what you are hoping to do:

    Nathan Nobis

  5. Rather than reviewing the techniques of other teachers and authors on logic. The surest path to logic is self-discovered. A tour of Douglas Hofstadter's "The Mind's Eye" or "I am a Strange Loop" will lead a well-directed student to create and/or discover logic within their own thought process, e.g. "Prelude...Ant Fugue" originally published in "Godel, Escher, Bach: An Eternal Golden Braid.

  6. One I don't think I've seen mentioned is Kelley's _Art of Reasoning_:

    (Has basic T/F & multiple-choice review.)

  7. I like P.D. Magnus's forallx, which Ron recommended. The list that Richard linked to is good, too.

    You might look at the Online Learning Center for Moore & Parker's Critical Thinking. See both the online exercises and the chapter overviews. I think students can get online versions of the text, too.


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