The Zariski topology, the Jacobian criterion and examples of simple algebras over a field k -- The Kahler 1-differentials -- Every k-algebra a which is essentially of finite type over k and simple is a regular local ring -- Brief discussion of unramified and étale homomorphisms -- Some corollaries to Theorem 3.5 -- Fitting ideals -- Proof of the Jacobian criterion and some characterizations of simple k-algebras and A-algebras -- Characterizations of simple A-algebras in terms of étale homomorphisms; invariance of the property of being a simple algebra under composition and change of base -- Descent of simple homomorphisms and removal of all noetherian assumptions in Chapter 7 and Chapter 8 -- Simple morphisms of preschemes and translation of previous theorems into the language of preschemes.