4 5 4 D O C U M E N T 4 6 0 J A N U A R Y 1 9 2 7 460. From André Metz “Les Cerisiers,” sentier de Paris, Sceaux (Seine), 20 January 1927 Dear Sir and Professor, If I am disturbing you again in the middle of your work, it is because I am in the middle of writing a book on the scientific philosophy of Mr. Meyerson. I’ve sub- mitted the manuscript to Mr. Meyerson himself, and he strongly advises (he de- mands, in fact) that I obtain your authorization for two passages in which you are mentioned. Here are the two passages: 1° Mr. Einstein himself pursued research on the path paved by Mr. Eddington, and later, in an entirely new direction, from strictly personal points of departure he had to abandon these points after having established that confronting them with the ¢facts² experimental results was impossible. At the present time, the positive and negative electrons, and even the properties of one or the other in the gravitational field and in the electromagnetic field, appear to be natural elements which are impossible to deduct one from another… 2° And again, my testimony is nothing next to that which the creator of the theory of relativity himself gave to Mr. Meyerson at the beginning of the year 1926. Having become acquainted with the book, La déduction relativiste, Mr. Ein- stein, profoundly struck by the ideas expressed therein, insisted on paying a visit to Mr. Meyerson during a trip to Paris, to give him his complete approbation and to express his admiration. “Hey now,” he said, “this demon of explanation, that I noticed in Descartes and in so many others, and that seemed so strange to me, am I therefore possessed by this demon too? That is something I have sus- pected about myself a hundred times. And now that I’ve read your book, I de- clare, I am convinced…” Indeed, I wrote these passages based on simple conversations, and yet one doesn’t have the right to use a private conversation without the permission of the person who spoke. I also await your permission to have the book published, at least in this form. I take this opportunity to ask you for news of your work, to wish you the best possible year in 1927, and to send you my cordial and sincere regards, André Metz Mr. Emile Meyerson has asked me to send his best regards also.