With the rising impact of science and technology on everyday life, scholars a re paying increasing attention to the roots of modern science and, not surprisingly, particular attention to the strange man who stands out as a giant in the world of physics.

‘Conceptual Analysis’

At the same time, the historians have changed their approcah. No longer content with flat chronologies of scientific developments, they now seek to understand the complex internal intellectual process by which individual scientists arrived at their conclusions.

The father of this technique, called “conceptual analysis,” was the late Alexandre Koyre of the Institute for Advanced Studies in Princeton.

It was the problem of applying this method to the complex and voluminous writings of Newton that prompted Dr. Koyre to begin a collaboration with Dr. Cohen 15 years ago to produce an edition of the “Principia” that would show the many changes it underwent in the course of three editions that came out under Newton's supervision from 1687 to 1726.

Dr. Koyre died in 1964, but Dr. Cohen pressed on alone with financial support from the National Science Foundation and the volume due next month, the “Introduction,” will be the first of six published jointly by Harvard and Cambridge University Presses. The “Introduction” alone will cost $25; the first edition cost 7 shillings in 1687.

Basically what Dr. Cohen has done is to have printed in facsimile the Latin text of the final (third) edition. Then this edition was compared word‐for‐word with the two previous editions and with four annotated and interleaved copies from Newton's personal library and the original manuscript. Every line is numbered and wherever a change appears in any of the other copies, it is printed below in a footnote.

‘A Living Document’

With these variant readings, according to Dr. Cohen, it is possible for the first time to read the work as “a living document” in which the evolution of Newton's basic ideas, methods of proof, philosophical outlook, general precepts and use of scientific data over a period of 39 years can be traced.