0 A Colloquial Survey of Jordan Theory
0.1 Origin of the Species
0.2 The Jordan River
0.3 Links with Lie Algebras and Groups
0.4 Links with Differential Geometry
0.5 Links with the Real World
0.6 Links with the Complex World
0.7 Links with the Infinitely Complex World
0.8 Links with Projective Geometry

I A Historical Survey of Jordan Structure Theory

1 Jordan Algebras in Physical Antiquity
1.1 The Matrix Interpretation of Quantum Mechanics
1.2 The Jordan Program
1.3 The Jordan Operations
1.4 Digression on Linearization
1.5 Back to the Bullet
1.6 The Jordan Axioms
1.7 The First Example: Full Algebras
1.8 The Second Example: Hermitian Algebras
1.9 The Third Example: Spin Factors
1.1 Special and Exceptional
1.11 Classification

2 Jordan Algebras in the Algebraic Renaissance
2.1 Linear Algebras over General Scalars
2.2 Categorical Nonsense
2.3 Commutators and Associators
2.4 Lie and Jordan Algebras
2.5 The 3 Basic Examples Revisited
2.6 Jordan Matrix Algebras with Associative Coordinates
2.7 Jordan Matrix Algebras with Alternative Coordinates
2.8 The $n$-Squares Problem
2.9 Forms Permitting Composition
2.1 Composition Algebras
2.11 The Cayley--Dickson Construction and Process
2.12 Split Composition Algebras
2.13 Classification

3 Jordan Algebras in the Enlightenment
3.1 Forms of Algebras
3.2 Inverses and Isotopes
3.3 Nuclear Isotopes
3.4 Twisted involutions
3.5 Twisted Hermitian Matrices
3.6 Spin Factors
3.7 Quadratic factors
3.8 Cubic Factors
3.9 Reduced Cubic Factors
3.1 Classification

4 The Classical Theory
4.1 $U$-Operators
4.2 The Quadratic Program
4.3 The Quadratic Axioms
4.4 Justification
4.5 Inverses
4.6 Isotopes
4.7 Inner Ideals
4.8 Nondegeneracy
4.9 Radical remarks
4.1 i-Special and i-Exceptional
4.11 Artin--Wedderburn--Jacobson Structure Theorem

5 The Final Classical Formulation
5.1 Capacity
5.2 Classification

6 The Classical Methods
6.1 Peirce Decompositions
6.2 Coordinatization
6.3 The Coordinates
6.4 Minimum Inner Ideals
6.5 Capacity
6.6 Capacity Classification

7 The Russian Revolution: 1977--1983
7.1 The Lull Before the Storm
7.2 The First Tremors
7.3 The Main Quake
7.4 Aftershocks

8 Zel'manov's Exceptional Methods
8.1 I-Finiteness
8.2 Absorbers
8.3 Modular Inner Ideals
8.4 Primitivity
8.5 The Heart
8.6 Spectra
8.7 Comparing Spectra
8.8 Big Resolvents
8.9 Semiprimitive Imbedding
8.1 Ultraproducts
8.11 Prime Dichotomy

II The Classical Theory

1 The Category of Jordan Algebras
1.1 Categories
1.2 The Category of Linear Algebras
1.3 The Category of Unital Algebras
1.4 Unitalization
1.5 The Category of Algebras with Involution
1.6 Nucleus, Center, and Centroid
1.7 Strict Simplicity
1.8 The Category of Jordan Algebras
1.9 Problems for Chapter 1

2 The Category of Alternative Algebras
2.1 The Category of Alternative Algebras
2.2 Nuclear Involutions
2.3 Composition Algebras
2.4 Split Composition Algebras
2.5 The Cayley--Dickson Construction
2.6 The Hurwitz Theorem
2.7 Problems for Chapter 2

3 Three Special Examples
3.1 Full Type
3.2 Hermitian Type
3.3 Quadratic Form Type
3.4 Reduced Spin Factors
3.5 Problems for Chapter 3

4 Jordan Algebras of Cubic Forms
4.1 Cubic Maps
4.2 The General Construction
4.3 The Jordan Cubic Construction
4.4 The Freudenthal Construction
4.5 The Tits Constructions
4.6 Problems for Chapter 4

5 Two Basic Principles
5.1 The Macdonald and Shirshov--Cohn Principles
5.2 Funda

On several occasions I and colleagues have found ourselves teaching a o- semester course for students at the second year of graduate study in ma- ematics who want to gain a general perspective on Jordan algebras, their structure, and their role in mathematics, or want to gain direct experience with nonassociative algebra. These students typically have a solid grounding in ?rst¿year graduate algebra and the Artin¿Wedderburn theory of assoc- tive algebras, and a few have been introduced to Lie algebras (perhaps even Cayley algebras, in an o?hand way), but otherwise they have not seen any nonassociative algebras. Most of them will not go on to do research in non- sociative algebra, so the course is not primarily meant to be a training or breeding ground for research, though the instructor often hopes that one or two will be motivated to pursue the subject further. This text is meant to serve as an accompaniment to such a course. It is designed ?rst and foremost to be read by students on their own without assistance by a teacher. It is a direct mathematical conversation between the author and a reader whose mind (as far as nonassociative algebra goes) is a tabula rasa. In keeping with the tone of a private conversation, I give more heuristicandexplanatorycommentthanisusualingraduatetextsatthislevel (pep talks, philosophical pronouncements on the proper way to think about certain concepts, historical anecdotes, mention of some mathematicians who have contributed to our understanding of Jordan algebras, etc.

 Kevin McCrimmon introduced the concept of a quadratic Jordan algebra and developed a structure theory of Jordan algebras over an arbitrary ring of scalars. He is a Professor of Mathematics at the University of Virginia and the author of more than 100 research papers.