A Distinctive Self-Study Book on Abstract Algebra
I recommend A Book of Abstract Algebra, which may be the best self-study book for abstract algebra.
This book has sparked considerable debate. Some believe it truly allows readers to grasp the essence of abstract algebra, while others think it is of little use. This divide mainly arises because the book differs from traditional textbooks. Standard textbooks must accommodate varying student backgrounds and often try to cover everything comprehensively, including types of exam problems. This book, however, is intended for those who genuinely love mathematics. Rather than mechanically teaching the definitions of theorems, how to prove them, and then solve exercises, it guides readers to understand why these definitions are formulated the way they are and to comprehend the concrete significance of structures in abstract algebra.

In fact, this issue is common in most textbooks. After studying them, students can solve problems and score well on exams, but if you ask whether they truly understand the theorems, the answer is often uncertain. For example, many students know the scenarios for applying Lagrange’s theorem, but are usually unclear about how the theorem itself was derived.
This book covers all the topics typically found in an introductory abstract algebra course, offering a completely different learning perspective. It abandons the traditional “theorem > proof > example” format, instead presenting material through informal discussions combined with thematic exercises. This approach enables readers to intuitively understand abstract algebra and cultivates the skill of thinking about problems like a mathematician. This method also aligns with the historical development of abstract algebra, where none of the concepts were defined a priori; rather, they were carefully abstracted by mathematicians from numerous concrete examples into the most stable forms. Definitions are the culmination of abstract algebra, and starting with them when learning is akin to reading history backward, making it difficult to foster genuine interest in the subject.
Another distinctive feature of the book is that many key ideas are embedded in the exercises; therefore, it is essential to complete all the exercises while reading.