I want to quote one review from Amazon:
4.0 out of 5 stars The True Meaning of this Book, November 11, 2000
By Leonardo Motta
I decided to write this review because I thought none of the reviews really mentioned the main focus of this book. This is not a book about Quantum Mechanics, nor molecular biology, nor neurobiology. In this book, the great Gell-Mann exposes his ideas of why all subjects of science (from physics, to chemistry, to biology, to psychology) must be studied together, why they are related and also he shows models of how to do this unified study. He defends that reductionism is not the only way of doing science, in opposition of the philosophical ideas of Steven Weinberg and Richard Feynman. This book is HIGHLY RECOMMENDED, because there aren’t many books that are against pure reductionism written by reductionism defenders. Gell-Mann is not against reductionism, but against PURE reductionism; he think its nice to explain a complex phenomenon based on the theory of its contents but its also important to study the phenomenon in his actual level, studying the way that the complex works. Not only the simple. Thats the origin of the name: Quark, the simple, and the Jaguar, the complex.