With the goal of helping students develop a good intuition for organic chemistry, this text approaches the material from a mechanistic viewpoint. The book presents twenty electron flow pathways as the building blocks of all the common mechanistic processes. Thus, students deal with a smaller number of reactant classes instead of studying each reaction as a separate case. It also uses physical models such as energy surfaces to aid the decision-making process; includes a unique chapter that teaches students how to make a multivariable decision; and contains advanced explanations using interaction diagrams and molecular orbital theory.