Why did Einstein tirelessly study unified field theory for more than thirty years? In this book, the author argues that Einstein believed he could find a unified theory of all of nature's forces by repeating the methods he thought he had used when he formulated general relativity. The book discusses Einstein's route to the general theory of relativity, focusing on the philosophical lessons that he learnt. It then addresses his quest for a unified theory for electromagnetism and gravity, discussing in detail his efforts with Kaluza-Klein and, surprisingly, the theory of spinors. From these perspectives, Einstein's critical stance towards the quantum theory comes to stand in a new light. This book will be of interest to physicists, historians and philosophers of science.

'… an impressive and important book … Einstein’s Unification is a unified, detailed, coherent, and convincing narrative about the path Einstein took after coming to general relativity and the reason for his all-consuming search for a unified theory of the forces of nature. Van Dongen’s book will deeply influence how we understand Einstein and how future biographies that try to relate all aspects of Einstein’s life will be written.'

Source: Isis

‘[This] book will be of interest to Einstein studies specialists, to historians and philosophers of science in general, and to scientists with any interest, professional or otherwise, in fundamental physics. The lay reader, provided they are reasonably well versed in physics, will find much to enjoy here also.’

D. Kennefick - University of Arkansas

‘Jeroen van Dongen’s remarkable book - an updated and revised version of his Ph.D. thesis of 2002, meanwhile matured through the author’s research in the Berlin group and subsequently at the Einstein Papers Project based at CalTech - offers a delightful tour through Einstein’s efforts … constantly analyzed from the dialectics of Einstein’s use of (pure) mathematics versus actual physics. The author thereby establishes - and this may be said to be the main point of the book - a gradual shift from the latter (which formed the strength of Einstein’s youth) to the former.’

N. P. Landsman Source: The Mathematical Intelligencer

'Van Dongen's book is an excellent resource for all who wish to understand Einstein more deeply, balancing the technical, the philosophical, and the historical with skill and judgment … By adding to his careful technical comments a nuanced, undogmatic treatment of the philosophical issues, van Dongen has made a truly valuable contribution to our understanding of Einstein.'

Peter Pesic - Notre Dame Philosophical Reviews

'… a superb account of Einstein's strategy in discovering the general theory of relativity …'

Source: Mathematical Reviews