Some time ago, I saw the below tweet about expensive logic texts:
— P.D. Magnus (@news4wombats) March 20, 2018
Now I feel rather strongly that assigning expensive textbooks is a horrible practice for students. They already pay quite a lot in tuition and housing, and for meals and medical care. All these things can and should change. But I want to focus on logic texts because this is something instructors have direct control over. Costly tuition and housing practically require large-scale institutional solution. Textbooks lie in our domain.
I claim that instructors should assign cheap introductory logic textbooks, preferably free or open-source ones. This is because:
- Cheap logic textbooks lessen the financial burden on our students.
- The introductory logic material is so well-understood that there are plenty of cheap logic textbooks available that cover all the instructor’s desired material.
So the one-two punch is: there are some tremendously good consequences of doing X, and practically doing X is so readily achievable. If you want some specific collection of topics (categorial logic + propositional deduction + propositional tables; propositional deduction & trees + first-order predicate deduction & trees; propositional deduction & trees & tables + first-order deduction; and so on), there is some book out there that covers at least all these topics. A partial list of logic course-ware and texts is given by Richard Zach here. (Check out the Open Logic Project, too, which has a number of builds you can pick to suit your needs!) And you may skip the stuff you do not want. Plus, there are plenty of cheap texts for informal fallacies in case you want something on that, too. (Check out An Illustrated Book of Bad Arguments!)
Now what are the reasons for doing otherwise, for instead assigning an expensive logic text in its 10th edition? One might offer the following:
- Most students can afford the expense or have external funds for it.
- The assignment and grading software is practically convenient, even practically necessary due to extraordinary enrollments.
So the one-two punch is that costs are neither a big problem, and they are practically convenient, sometimes even practically needed. My suspicion is that many instructors assign an expensive book out of habit or because the software is more convenient. Perhaps there is also a feeling that our job as instructors is not to solve the problem of making higher education affordable. Mostly, I expect the basis for this practice is habit.
Now (1) is false. Even if it were not false, it would not justify choosing an expensive logic textbook over a cheap one. It only suggests that both are permissible. And if both using a cheap textbook and using a costly one are permissible, then given the availability of cheap and adequate alternatives, why use a costly one?
Now (2) is more interesting. But it is still insufficient. Assessment is part of our job, and it can be done without making students pay a cost for it. (Some of the links above include logic quiz generators. Some open-source software even allows for automatic grading of proofs or translations.) And if you really are teaching so many students that assessment takes too much time—there are teachers who have large lecture-style logic courses that are practically infeasible to grade by hand themselves—then it would actually be cheaper to hire a grader using a “student fee” rather than make all your (say) 100+ students pay $100+ for logic software. So if practical convenience or need is the reason, then there is a practically cheaper alternative that does more good. And finally—this is the real kicker—there already is free online software that does grading for you. (Just check out Graham Leach-Krouse’s Carnap project.)
So logic books in my courses are, and will continue to be, freely available, either through my institution’s library or elsewhere. I might add that pretty much all of the above applies equally to introduction to philosophy anthologies.