Mathematical Digest Short Summaries of Articles about Mathematics in the Popular Press "L'Incroyable Efficacite des Mathematiques," by Dominique Lambert. La Recherche, January 1999, pages 4855. This article explores what physicist Eugene Wigner famously called "the unreasonable effectiveness of mathematics in the natural sciences." A mathematical theory that is thoroughly effective, writes Lambert, is a formalism endowed with capacities for prediction and explanation and for generating new ideas; or, said differently, it is a language that permits description, explanation, and mastery of phenomena. With examples of some of the most spectacular mathematical and scientific achievements of the century, the article analyzes what makes certain mathematical ideas especially rich and fecund.  Allyn Jackson
