It is comparatively little known that the first important papers of Einstein laid down the foundations of classical statistical mechanics almost at the same time and independently of Gibbs. These papers are important on the one hand because Einstein's path is more direct and satisfactory than Gibbs', and on the other hand because they allow to understand how Einstein was led to the scientific program tackled in his works on statistical physics in 1905, i.e., the photon and the Brownian motion papers. I shall describe the papers, set them in context, and recall how the original traits in this approach resurfaced in his later work.
Angelo Vulpiani