Beginnings of a new science. D'Alembert's Traite de dynamique and the French Royal Academy of Sciences around 1740

D'Alembert entered the European scientific scene with the publication of his first book: the Traite de dynamique (1743). Dynamics had only become a specific area of study in the 1730s, so with the Traite D'Alembert established himself as one of the main protagonists of this new science. Unfortunately, historians have not yet uncovered any manuscripts or letters that might provide insight into the circumstances in which this book was written. The present article aims to clarify some of these circumstances and to give essential characteristics of D'Alembert's dynamics, in particular in the light of the works led by his colleagues at the French Royal Academy of Sciences. Additional information can be gleaned from reading D'Alembert's ideas about causality and the proofs of some mechanical principles, in researching how he could have known some mechanical problems which appeared in the Academy around 1740, and in analyzing how he solved them. From such studies it is possible to sketch hypotheses about the formation of the young man. This almost certainly involved exchanges or competition with his colleagues, which probably played a role in his discovery of some mechanical problems. Although it was D'Alembert who eventually published the first book exclusively dedicated to the science of dynamics, with an original and specific approach which he kept during all his scientific career, an approach that allowed him to write that his work had nothing in common with that of the others.