I maintain that, with the possible exception of math majors and philosophy majors (and maybe not even in those cases), undergraduates are better served by a serious course in inductive logic than they are by a course in deductive logic. (A real course in introductory inductive logic, that is, not a critical thinking course.) There are at least a few inductive logic textbooks that are suitable. I like this one: Argument & Inference: An Introduction to Inductive Logic.

That said, I do like teaching symbolic logic, and sometimes there are reasons for doing so. I used to teach it with Allen & Hand’s Logic Primer. In the fall of 2019, however, I began teaching Intro to Logic online, and, since the Logic Primer isn’t a great choice for an online course, I started looking for a new textbook that included software. I found Graham Leach-Krouse’s Carnap website, which is free and is used online. (So, there’s nothing to download.) And, for a textbook, I chose forallx: Calgary, which, after some revisions, became forallx: the Mississippi State edition.

Since the course that I was teaching was an online, 100-level course, I decided to only go through truth tables and propositional logic (plus some introductory material). I removed chapters that I wouldn’t need, and I added further explanation to many of the chapters that I kept—in particular, with a eye toward explaining the material to online students. I also added a few sections on using Carnap, and I made sure that the truth tables and proofs in forallx matched the format used in Carnap.

I begin the course with pp. 1 – 11 of Argument & Inference. (There are lots of, more or less, similar ways to introduce students to arguments and validity. I’m partial to how I did it in Argument & Inference, and so I use it.) The first two chapters of forallx: the MSU edition cover the same material however. Using those chapters, this is one way to organize a course.

For the part of the course on derivations, my goal is that the students reach the point where they are able to give proofs of DeMorgan’s laws and construct other proofs of similar difficulty. What I have labeled “soundness and completeness” is really only a pair of homework assignments in which the students are given arguments and have to determine if each is valid or invalid. For each, if it is valid, they have to give a proof; and if it is invalid, they have to construct a truth table and identify the invalidating assignment.

08/14/2023 update For some of the sections of Intro to Logic that I teach in the classroom, I’ve dropped theorems and the soundness and completeness of TFL (from the last two weeks of the course) and added an introduction to first-order logic (i.e., its syntax, translations, and simple proofs).

I am still working on this textbook, and so every once in a while it gets revisions and improvements. Anyone can use it, and if you have suggestions, questions, or need advice on using Carnap, feel free to contact me.