Although learning is achieved through different resources and experiences from generation to generation, the need to establish a construct (like the ABCs for spelling) remains immutable. I have spent the better part of three decades teaching the principles that underlie kidney disease. Much of my teaching takes place in an experiential setting (i.e., during patient rounds). This work reflects a distillation of these experiences. The book relies heavily on simple media (illustrations, algorithms, and photomicrographs) to deliver content. I have also included incremental, reflective questions, so that readers can test their comprehension and experience how that content can be applied to the clinical setting.