The De concordia, published by Juan Luis Vives in 1529 and dedicated to the Holy Roman Emperor, Charles V, is a comprehensive analysis of the social and political problems which were then afflicting Europe. It is the only such analysis undertaken by any of the Renaissance humanists. The De concordia merits a much more important place in Vives' oeuvre than scholars have hitherto given it. It is structured around the Augustinian concept of concordia and its antithesis, discordia. As such, it is an explicit attempt to understand current history in metaphysical terms. Vives' intention is not to give strategic or tactical advice to Charles V, but to examine the general disorder of Europe with a view to determining its fundamental nature and significance. This is the first critical edition of the De concordia and the first English translation.