From Kenneth Ellman, Box 18, Newton, New Jersey 07860, ke@kennethellman.com<br>"I hope that, decades from now, when I and my other books have been forgotten, this will still be useful to scholars and students".  So spoke Harvard University Professor I. Bernard Cohen some years before his death in 2003. His co-translator Anne Whitman had died in 1984. The translation and the extraordinary commentary is 974 pages long and took 15 years to complete. I have had this edition for many years and in reading it again I decided to write this review.  I feel grateful to Cohen and Whitman for what they accomplished.<br><br>This particular edition by Cohen and Whitman of The Principia stands alone (as far as I know) in making one feel that a teacher, guide, and historian are holding your hand while exploring and understanding one of the most dramatic and powerful scientific and mathematical treatise ever written. I am surprised at some of the reviews here in that they seem to discuss the applicability or utilization of The Principia as a Physics or Math textbook. This is certainly not a textbook in the modern sense in any respect. This is not a book you would use to prepare for any normal Physics or Math examination. It must be kept in mind that this book by Newton was a human accomplishment and this particular edition with its extensive commentary by Cohen lets one be exposed to both the scientific rigor and social aspects of the world of Isaac Newton. And due to the fact of Newton's extraordinary scientific and mathematical accomplishment it caused historical alteration in the course of human events as does each great expansion of human knowledge. Sometimes when mathematical expressions and concepts of Physics are portrayed we forget that the ideas are first and foremost a human experience, it is not some distant and inscrutable theory but part of our most intimate life. We try to understand what we are and where we are. In the days of Isaac Newton Natural Philosophy was thought of as an expression and search for the truth and mathematics was sometimes able to be the handmaiden of this exploration. Unfortunately, from my point of view, philosophy has become detached from much of mathematics and this has done a disservice to both Physics, Math and what is currently thought of as Philosophy. I see no advantage in this current day separation and when immersing yourself in this edition of The Principia, there is a longing for those days now past when there was a unification of science and philosophy.<br>There is little reason in this review to explain the significance both mathematically and historically of the writing of Isaac Newton. Whether a student is using a conventional Physics textbook to master the understanding, laws and calculations described in The Principia or is exercising physics problems to show facility and prepare for an examination, each and every aspiring learner is obligated to master the ideas and knowledge as expressed in The Principia one way or another. Certainly our current day Physics textbooks do not teach as Isaac Newton taught and wrote. The Principia is not a book normally used to prepare for any Physics examination whether in High School or University. But the law of science and math as expressed in The Principia is as valid in general application today as it was in 1729. Our understanding of the laws of Newton as they relate to later discovered equations and expressions, including Relativity, does alters our knowledge of applicability of Newtonian physics. It does show the limitations of our belief in the immutable Laws of Nature, including those mathematical laws. In some respects radically so. So, it really depends upon the demands you put upon the math and knowledge as expressed in The Principia. Do not read Isaac Newton in the light of Albert Einstein and others. First read Newton in the light of his age, then step back and remember how we have continued along this amazing path to knowledge. So The Principia is another place in our human endeavor. This is not just a book for mathematicians. As related on pages 297 and 298 that wonderful contemporary of Newton, John Locke, without benefit of full mathematical understanding was still able to comprehend the ideas within. So will you. This is by far the best edition of The Principia I have ever read. Kenneth Ellman, Box 18, Newton, New Jersey 07860 , ke@kennethellman.com