Erdős thought God had a book of proofs. I think he was slightly off the mark: God has a book of abstractions, and the good proofs are the ones which use abstrac

Erdős thought God had a book of proofs. I think he was slightly off the mark: God has a book of abstractions, and the good proofs are the ones which use abstractions from the book most judiciously. Anyhow, algebraic effects are in The Book.