logicmatters.net

Logic Matters (logicmatters.net) is the personal academic website and blog of Peter Smith, a logic author and teacher. It is best understood as a hub for freely available logic textbooks, study guidance, and occasional writing on logic, music, and other interests. If you are looking for open-access introductions to formal logic, Gödel's theorems, or category theory—or a reading roadmap for mathematical logic—this site is directly useful. If you want a formal course with enrollment, grading, or institutional support, it is not that; it is a collection of self-study materials.

Who runs it and what it covers

The site is maintained by Peter Smith and centers on his own teaching and writing. The homepage describes it as hosting "Peter Smith's occasional blog posts on logic, music, and other enthusiasms," with recent posts listed by date. The content spans:

• Logic textbooks — including An Introduction to Formal Logic and two books on Gödel's theorems
• Study guidance — a widely downloaded study guide and book notes
• Category theory — introductory and intermediate resources
• LaTeX for logicians — resources for typesetting logic
• A blog and archive — posts, papers, and reviews

The main resources

The "Five Big Red Logic Books"

The site's headline section states plainly that these books "are open access." This is the central draw: full texts made freely available rather than sold.

Introduction to Formal Logic

A corrected version of the second edition of An Introduction to Formal Logic is freely available on the site. The page also links to answers to the exercises and to various supplementary materials—useful if you are working through the book independently and want to check your work.

Gödel's Theorems

Two books are freely available: An Introduction to Gödel's Theorems and the much shorter Gödel Without (Too Many) Tears, along with related materials. The pairing matters: one is a fuller treatment, the other a condensed route into the same material.

Category Theory

The site collects introductory and intermediate resources such as lecture notes and freely available books, including Smith's own Introducing Category Theory.

The Study Guide and Book Notes

Beginning Mathematical Logic: A Study Guide is described as "much-downloaded." It comes with an appendix reviewing wider-ranging books on mathematical logic, plus links to roughly forty further book notes. This is the section to start with if your goal is to plan a course of reading rather than dive into a single text.

Archive and LaTeX

The archive links to older blog posts, papers, reviews, and other pieces. The LaTeX section points to resources for logicians, philosophers, and others using LaTeX.

How to decide whether to use it

The main limitation to keep in mind: this is a personal site built around one author's materials and recommendations. It is not a comprehensive index of all logic resources, and it does not present itself as offering structured courses or credentials. Treat it as a high-quality starting library and reading guide, and verify current availability of any specific file on the site itself, since the homepage notes a last update of September 29.

Logic Matters hosts Beginning Mathematical Logic: A Study Guide, a freely downloadable guide for planning a mathematical logic reading path, plus an appendix reviewing wider-ranging books on the subject and links to roughly forty further book notes. It suits self-directed learners who want a structured route through the material and help deciding which books to read. The site also offers free access to several logic textbooks, so you can combine the guide's recommendations with the actual texts.

What the study guide gives you

The study guide is the site's central planning document. Rather than teaching logic itself, it maps the field and points you toward books at each stage. The appendix extends this by reviewing broader books on mathematical logic, which helps when you want a wider survey rather than a single focused text.

Around forty book notes accompany the guide. These are the practical comparison layer: notes on individual books let you judge level, style, and coverage before committing to one.

Building a reading plan

A workable approach:

1. Download the study guide and read its overall structure first, without picking books yet.
2. Identify the subareas you need (for example, propositional logic, first-order logic, computability, set theory, or Gödel's theorems).
3. For each subarea, shortlist the guide's recommendations.
4. Cross-check your shortlist against the relevant book notes to compare level and approach.
5. Check the appendix if you want a broader or alternative treatment.
6. Pair your chosen book with the free texts below where they overlap.

Free texts you can pair with the plan

The site states that the headline "Five Big Red Logic Books" are open access, and several individual works are freely available:

If your plan reaches Gödel's theorems, the two Gödel books let you choose depth: the longer introduction for a full course, the shorter one for a faster pass. Exercise answers for the formal logic text mean you can self-check as you work.

Other sections worth using

• Category theory: links to introductory and intermediate resources, including lecture notes and freely available books.
• LaTeX for logicians: resources for logicians, philosophers, and others using LaTeX — useful once you start writing up proofs or notes.
• Blog: occasional posts on logic and other topics; recent entries have covered proof theory and reading recommendations.
• Archive: older blog posts, papers, reviews, and other pieces.

Practical notes

The study guide is described as "much-downloaded," and the site presents the key texts as open access, so you can begin without a purchase decision. Start with the guide's structure, use the book notes to choose, and treat the free textbooks as the working texts for your plan.

Logic Matters provides two freely available books on Gödel's theorems: An Introduction to Gödel's Theorems and the much shorter Gödel Without (Too Many) Tears, along with related materials. If you want a full, structured treatment, start with the longer book; if you want a fast route into the core results, start with the shorter one.

The two books

Both are described on the site as freely available. The site does not present them as substitutes for each other so much as different entry points: one is the extended introduction, the other is the condensed version.

Related materials

The Gödel section is not limited to the two books. The site also points to related materials for the same topic, so once you have chosen a book you can look for supporting items alongside it.

How to choose

• Choose An Introduction to Gödel's Theorems if you are working through the subject systematically and want the fuller treatment.
• Choose Gödel Without (Too Many) Tears if you want a shorter account first, or if you want to see the shape of the results before committing to the longer book.
• Use both if you want the concise version as an overview and the longer book for detail.

Where this fits on the site

The Gödel material sits alongside other Logic Matters resources, including An Introduction to Formal Logic (a corrected second edition, freely available, with exercise answers and supplementary materials), category theory resources, and Beginning Mathematical Logic: A Study Guide with its appendix and book notes. If your goal is broader than Gödel, the study guide is the natural starting point; if your goal is specifically the incompleteness results, go directly to the two Gödel books.

Logic Matters hosts a dedicated section, LaTeX for Logicians, that collects links to resources for logicians, philosophers, and others who use LaTeX. The site describes it as pointing to "a wide range of resources of interest to logicians, philosophers and others using LaTeX." If you typeset logic symbols, proof trees, or formal documents and want a curated starting point rather than scattered search results, this section is the entry to check. Note that the site only describes the section's scope; it does not list the individual tools or packages on the page evidence available, so treat it as a directory to explore rather than a single download.

What the LaTeX section covers

Based on the site's own description, the LaTeX for Logicians pages are organized as pointers to resources rather than a self-contained package. The stated audience is:

• Logicians
• Philosophers
• "Others using LaTeX" for related academic work

The emphasis is breadth: the section links out to a range of materials rather than hosting one tool. This makes it most useful as a hub when you already know you need LaTeX support for logic-heavy documents and want a maintained list of options.

How it fits with the rest of Logic Matters

The LaTeX section sits alongside the site's other resource collections, which are all openly accessible according to the site:

If your goal is document preparation rather than reading logic itself, the LaTeX section is the relevant one; the other sections support study and reference.

Practical steps to use it

1. Go to logicmatters.net and locate the LaTeX FOR LOGICIANS link in the site navigation.
2. Open the section and review the linked resources to find ones matching your task (for example, typesetting proof trees, logic symbols, or formal notation).
3. Follow the individual links to the external resources, since the section itself is a pointer collection.
4. Check the site's update note (the page shows "Site updated: September 29 @ 18.54") to gauge how current the listing is.

Expected result: you reach a curated set of LaTeX resources aimed at logic and philosophy writing, rather than having to assemble them yourself.

Common sticking points

• It is a directory, not a download. The page evidence describes links to resources, so do not expect a single installer or template from the section itself.
• External links may change. Because the section points outward, individual resources depend on their own hosts staying available.
• No pricing is stated for the LaTeX section. The site describes several books as open access or freely available, but the page evidence does not state terms for the LaTeX resources specifically, so verify conditions at each linked destination.

When this is the right resource

Use the Logic Matters LaTeX section if you are a logician or philosopher who wants a maintained, curated list of LaTeX resources for formal and academic documents. If instead you need free logic textbooks or study material, the site's other sections (Intro to Formal Logic, Gödel's Theorems, the Study Guide) are the better fit.

Logic Matters, Peter Smith's site, hosts several complete logic textbooks and study guides as open-access downloads, plus a large set of book notes and LaTeX resources for logicians. The free materials cover formal logic, Gödel's theorems, category theory, and a general study guide to mathematical logic. Everything listed below is described on the site as freely available; the site does not state any price, account, or login requirement for these downloads.

The main free textbooks

The site also refers to "The Five Big Red Logic Books" as open access, which is the headline framing for the textbook collection.

How to choose between them

• New to logic entirely: start with An Introduction to Formal Logic, then use the linked exercise answers to check your work.
• Want the shortest route into Gödel: read Gödel Without (Too Many) Tears first; go to An Introduction to Gödel's Theorems if you want the fuller treatment.
• Deciding what to study more broadly: Beginning Mathematical Logic: A Study Guide is designed for exactly this — it maps the subject and its literature rather than teaching one topic.
• Interested in category theory: use the category theory page, where Introducing Category Theory sits alongside lecture notes and other free books at introductory/intermediate level.

Beyond the textbooks

The site's Study Guide and Book Notes section pairs the study guide with an appendix and links to roughly forty further book notes — short reviews/notes on individual logic books. These are useful when you already have a reading list and want an assessment before committing time to a title.

There is also a LaTeX for Logicians section, pointing to resources for logicians, philosophers, and others who use LaTeX. If your work involves typesetting logic (proof trees, symbols, tableaux), this is the part of the site to check.

Practical notes

• The site is organized into clear sections: Blog, IFL (the formal logic book), Gödel, Categories, Study Guide, Archive, and LaTeX for Logicians. Navigating by section is faster than searching.
• The blog carries occasional posts on logic and related topics, and the Archive collects older posts, papers, and reviews — useful if you want commentary rather than textbooks.
• The site was last updated September 29 (18:54), so the download links reflect a maintained collection rather than an abandoned one.

If your goal is simply to get a free, self-contained logic textbook today, An Introduction to Formal Logic is the direct starting point; if your goal is to plan a longer course of study, download Beginning Mathematical Logic: A Study Guide first and let it point you to the rest.