In the last few years the topic of differentials has occupied the attention of a good many teachers of mathematics. Since the appearance in 1931 of my article advocating the teaching of the Differential Calculus from the differential standpoint right from the start, very divergent views have been expressed on this question and there was a general discussion on the topic at the annual meeting of the Mathematical Association in 1934. This article, the subsequent correspondence and the discussion have certainly brought into evidence the fact that many mathematicians still have a very obvious distrust of “differentials” and they seem unable to clear their minds of some early prejudice against the employment of differentials for any purpose.