1. Why Algebra: Chapter 0 Is Different Paolo Aluffi’s Algebra: Chapter 0 (AMS, 2009) is not your typical algebra textbook. Its unique selling point is explicit: it introduces category theory from the very first chapter, long before groups, rings, or modules. The “Chapter 0” is a full introduction to categories, functors, and universal properties.

| Chapter | Topic | Exercise difficulty (1–5) | |---------|-------|----------------------------| | 0 | Introduction: Categories, functors, natural transformations | 3–4 | | I | Groups, first look | 2–3 | | II | Groups, deeper (Sylow, solvable, simple) | 4–5 | | III | Rings and modules | 4 | | IV | Linear algebra over rings (including canonical forms) | 4–5 | | V | Field theory and Galois theory | 4 | | VI | Homological algebra (projective/injective, Ext, Tor) | 5 | | VII | Universal constructions (limits, adjunctions) | 5 |