First published in 1985, Origins of Life by Freeman Dyson, is a great introduction into the most accepted theories on the origins of life. It was almost universally assumed that the first organisms sustained themselves, in a very hostile world 3 eons ago, by replicating themselves. A brief introduction into the three main theories of replication, a precise chemical process a molecule uses to make an exact copy of itself, is laid out in the first two chapters. Dyson then presents his own theory as to the possibility that the first organisms didn't replicate, but sustained themselves via metabolism, in the form of simple enzymes. He theorized that replicating organisms used the pre-existing enzymes as hosts later on. In chapter three, he presents a "simple" mathematical model as a basis for biologists to create their own experiments to, if nothing else, prove him wrong (Dyson is a theoretical physicist and this work attempts to bring together thinking from different scientific fields). The last chapter was the best, bringing philosophy into play. For example, he debates the notion that replication of human behavior is not a very exact process, but very fault tolerant instead. In fact, he surmises the first replicating organisms were probably sloppy at the job. If that notion excites you, buy this book! Mr. Dyson attempts to make this book readable for the layman, but does not define what monomers or nucleotides are. This book is not for everyone. A rudimentary understanding of biology would help, but I made it with only a dictionary. I didn't even attempt to follow the math in chapter three, and the author was apologizing for its simplicity!