I picked up this book because it looked like an interesting read. A surgeon from the turn of the century inquiring to the state of knowledge about mankind in both the physical sense and in social dynamics of human civilization. I didn't expect this book to take me down the path it took me especially as I began to research the author. The book is very well written, it was a best seller of it's day. This copy is probably a sixth edition that was reprinted in 1938 and based on the note in the front, gifted to someone's father that year. Now, if you study history, maybe it should set off some red flags for you that a book discussing the biology and sociology of man, which became popular in 1935 and is written by a biologist. Welcome to my deep dive into Eugenics and not the physical health version of the 1910's, but the disgusting sterilization of the unwanted gene pool and the euthanizing of people with severe mental illness. Not only did this book boost the ideas that lead to the actions and policies of the Nazi party in 1940's Germany, but the author himself after working closely with the Rockefeller Institute of Medical Research, which has it's own shady past, traveled home to the awful puppet run, Nazi occupied France to work with the Nazi's directly in solving "human problems". The story from there get's a little opinionated. There are many who believe that had Alexis Carrel survived long after the liberation of France, he may have faced a war crime tribunal for his work with the Nazi's in Eugenics. The book it'self doesn't read like a work of great evil. He mostly dances around the ideas with the exception of a few moments of brutal honesty which now read with a very heavy dark shadow looming over the words.