Category Theory Illustrated
Shares rank 14 of 20 mathematics textbooks by recommenders
Recommended as a clear, light introduction to category theory and a companion to Visual Category Theory Brick by Brick. One critic says it misstates central theorems.
Recommended as a clear, light introduction to category theory and a companion to Visual Category Theory Brick by Brick. One critic says it misstates central theorems.
4 people gave an opinion
- recommend it
- 3
- criticize it
- 1
- approval share
- 75%
Recommended in 3 of 13 months
- November 2025: not recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 3 people recommend itNeeds 10 or more, not met.
- 3 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 3 of 13 monthsNeeds 4 or more, not met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Clear, light introduction to category theory
“appears to be clear and well explained enough to give a light introduction to category theory”
Comment from 18 Apr 2026 in “Category Theory Illustrated – Orders” Companion to Visual Category Theory Brick by Brick
“It's an exciting work because between Visual Category Theory Brick by Brick and its reading lists, Category Theory Illustrated promises to fulfill”
Comment from 19 Jun 2026 in “Category Theory Illustrated: From Sets to Categories” Author's related book appreciated
“I also appreciated taking a look at the authors book, Category Theory: Illustrated”
Comment from 22 May 2026 in “The case against boolean logic”
What people warn about
Each mark is one comment
Misstates central category theory theorems
“where it misstates central theorems in CT”
Comment from 22 May 2026 in “The case against boolean logic”
Other mathematics textbooks people recommend
The four most recommended other mathematics textbooks, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Algorithms for Optimizationby Kochenderfer and Wheeler | 10 | 1 | 91% | 1 | — | — |
| Mathematics for Computer Scienceby Lehman, Leighton and Meyer | 8 | 4 | 67% | 1 | — | — |
| Numerical Recipesby Press et al. | 7 | 1 | 88% | 5 | — | — |
| Concrete Mathematicsby Graham, Knuth and Patashnik | 7 | 0 | 100% | 4 | — | — |
| Category Theory IllustratedThis page | 3 | 1 | 75% | 3 | — | — |
What people said
All 4 comments that mention it, newest first. Each links to the original comment.
“It's an exciting work because between Visual Category Theory Brick by Brick and its reading lists, Category Theory Illustrated promises to fulfill”
“I also appreciated taking a look at the authors book, Category Theory: Illustrated”
“where it misstates central theorems in CT”
“appears to be clear and well explained enough to give a light introduction to category theory”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.