This monumental work is the ripe fruit of a lifetime of observation, research, and meditation on the human organism and the remarkable diversity of our closest animal relatives: the mammals. Its first German edition (1971) was followed in 1977 by an English translation (Man and Mammals) that was soon out of print. By its second German edition in 2012, the work had doubled in size to 22 chapters in two volumes. These are included in the present English edition along with a new chapter on armadillos, anteaters, sloths, and pangolins. The English translation of 1977 has been significantly expanded and brought up to date, the two chapters on mammalian embryology that were left out of that edition have been included, and the entire 23-chapter work has been revised by the author.

Within the approximately 5,400 species of mammals, there is a baffling diversity ranging from the Etruscan shrew, barely an inch long, to the 100-foot-long, over 200-ton blue whale. And yet all mammals share a common organizational structure: Through their sensory and nervous system they perceive their surroundings and process their perceptions; through their metabolic-limb system they take in and digest nourishment and move through their surroundings; and mediating between these polar opposite systems, they each have an integrated, rhythmic respiratory and circulatory system.

Why are shrews so small and whales so large? Why do many hoofed mammals have horns, and why do deer have antlers? Why do least chipmunks have dorsal stripes that run parallel to their spine while tigers have stripes on their flanks that run parallel to their ribs? According to the dominant Darwinian paradigm, such features are usually explained as the result of random mutation and natural selection--of factors external to the organism itself. In Understanding Mammals, Wolfgang Schad, building on the pioneering morphological insights of Goethe, shows how the extraordinary diversity of shapes, sizes, dentition, coloration, behaviors, preferred habitat, and even embryonic development among the mammals reflect the unique configuration of the three organ systems within their particular constitutions. He thus establishes the basis for a new scientific understanding of the mammals in which each unique organism explains itself. A century from now this groundbreaking work may well be accorded the same paradigm-shifting importance as Darwin's Origin of Specieshas enjoyed for 150 years.

The first three chapters give an in-depth description of the three main organ systems. Schad shows how they function together in a balanced way in the human being while one system predominates in the other mammals. He then shows in detail how the rhythmic system dominates in the carnivores, the metabolic-limb system in the ungulates, and the nerve-sense system in the rodents. He finds, for example, that, though they are primarily dominated by the nerve-sense system, rodents such as the porcupine or beaver exhibit a secondary emphasis on the metabolism, whereas squirrels display secondary characteristics of the rhythmic system, and mice exhibit purely nerve-sense characteristics. In beautiful chapters on antelopes and deer, he describes how even the formation of their horns and antlers corresponds with their particular constitutions.