A new introductory logic textbook has just arrived, Greg Restall and Shawn Standefer’s *Logical Methods* (MIT).

This promises to be an intriguing read. It is announced as “a rigorous but accessible introduction to philosophical logic” — though, perhaps more accurately, it could be said to be an introduction to some aspects of formal logic that are of particular philosophical interest.

The balance of the book is unusual. The first 113 pages are on propositional logic. There follow 70 pages on (propositional) modal logic — this, no doubt, because of its philosophical interest. Then there are just 44 pages on standard predicate logic, with the book ending with a short coda on quantified modal logic. To be honest, I can’t imagine too many agreeing that this reflects the balance they want in a first logic course.

Proofs are done in Gentzen natural deduction style, and proof-theoretic notions are highlighted early: so we meet e.g. ideas about reduction steps for eliminating detours as early as p. 22, so we hear about normalizing proofs before we get to encounter valuations and truth tables. Another choice that not everyone will want to follow.

However, let’s go with the flow and work with the general approach. Then, on a first browse-and-random-dipping, it does look (as you’d predict) that this is written very attractively, philosophically alert and enviably clear. So I really look forward to reading at least parts of *Logical Methods* more carefully soon. I’m turning over in my mind ideas for a third edition of *IFL *and it is always interesting and thought-provoking to see how good authors handle their introductory texts.

Henk MüllerAnd a more mundane point, a lot of basic and challenge questions but no answers or suggestions whatsoever. I wrote MIT about it. I have been trained as philosopher and arabist/iranist

Arabic is quite difficult to master. so imagine a book on intermediate to advanced level Arabic with lot of questions and no answers at all. Sainsbury’s is the only other logic book I know off who does the same. Why? Making students frustrated, trying to keep only the excellenti on board? Save paper? Only God knows.

Chris GrantIt’s a textbook. There’s a perception among some of us teachers that homework loses its summative value when the answers are in the back. Sure, students can probably track down the solutions online, but I feel like students take me a little more seriously when I ban looking up answers online than when I ban looking up answers in a textbook that they’ve paid for.

Logic textbooks on my shelf here that have exercises without answers in the back include Hinman, Tourlakis, Enderton’s Computability Theory, Kunen’s Foundations, Hodges’ Model Theory, and Our Host’s An Introduction to Formal Logic.

Michael FlynnYes I agree with Mr Müller – Logic is a language and teachers of Logic should take a leaf from language texts which always provide answers to questions or tests.

Restall’s approach of asking only questions and providing no answers, flies in the face of centuries of language learning.

Taken to its extreme the argument by Mr Grant would be for all “students” to be autodidacts. It is also deeply disrespectful to assume all students would not want to learn by attempting the quiz and then checking their own work. Thankfully there are excellent logic books that do provide question and answer: Girle’s Introduction to Logic and Bergmann et al The Logic Book are two that I enjoyed.

Henk MüllerDear sir, thank you for your thoughts, I could not agree more. I have another example. I bought Humberstone’s book on philosophical applications of modal logic. I was interested because it implied it would delve deeper in the kind of topics in philosophy of religion in which modal logic is essential. The book started as a lecture course in modal logic for

philosophy undergraduates. I missed mister Smiths short review that made clear that it was very advanced. He was right. Its far too difficult. I admire the undergraduates who understood it. Also in this book there were omly exercises without answers

I asked the author about them, he adviced me to look for someone to help me out.

Chris Grant1. There is a linguistic aspect to logic, but I don’t think that a language is all that logic is.

2. Many language texts do not provide answers to all their exercises. For example, _Das Erste Jahr_ by Bluske and Walther, _German: A Structural Approach_ by Lohnes, et. al., _German_ by Rehder and Twaddell, and _Sprich Mal Deutsch_ by Rowlinson (chosen at random from my campus library) all have some exercises that don’t have solutions provided.

3. Wikipedia characterizes autodidacticism as “education without the guidance of masters (such as teachers and professors) or institutions (such as schools)”. I don’t see how texts withholding solutions to some exercises makes it easier to dispense with teachers. My students seem to consider me to be something of a solutions manual!