Rarely is one invited to see the ingredients that go into the sausage, and if one plans only to eat sausage, this is an ideal situation. But the only way to make sausage is to take a close look at these ingredients, blemishes and all. Despite modeling shortcomings and disagreements that are evident among the authors, Elements of Reason is a remarkable book, both for its instructional value and the insight it offers into one of the most important problems in the social sciences.