Take for example the Italy of the sixteenth century, which is evidently in decadence; but while it is declining, it transmits to the rest of Europe its intellectual weapons. These are not all that pass to the civilization which continues, but even the world market establishes itself upon the foundation of those geographical discoveries, and those discoveries in the naval art, which were the work of Italian merchants, travelers and sailors. It is not only the methods of the art of war and the refinements of political diplomacy which passed outside of Italy (though it is only with these that men of letters ordinarily concerned themselves), but even the art of making money, which had acquired all the evidence of an elaborate commercial discipline, and one after the other the rudiments of the science, upon which is founded modern technique, and to begin with all the methodical irrigation of fields and the general laws of hydraulics. All that is so precisely true, that an amateur in conjectural theses might come to the point of asking himself this question: what would have become of Italy, in this modern bourgeois epoch, if, executing the project of the Venetian Senate (1504) of making something which would have resembled in its effects a piercing of the Isthmus of Suez, the Italian navy had found itself in a direct struggle with the Portuguese in the Indian Ocean, at the very moment when the shifting of historical activity from the Mediterranean to the ocean prepared the decadence of Italy? But enough of fantasy! A certain historical continuity, in the empirical and circumstantial sense of the transmission and the successive increase of the means of civilization, is then an incontestable fact. And, although this fact excludes all idea of preconceived design, of intentional or hidden finality, or pre-established harmony, and all the other whimsicalities in regard to which there has been such a deal of speculation, it does not exclude, for all that, the _idea of progress_, which we can utilize as an _estimation_ of the course of human development. It is undeniable that progress does not embrace _materially_ the succession of generations, and that its conception implies nothing categorical, considering that societies have also been in retrogression, but that does not prevent this idea from serving as a guiding thread and a _measure_ to give a meaning to the historical _processus_. There is no common ground for critics who are prudent, in the use of specific concepts as in the method of their application, and those poor extreme evolutionists, who are scientists without the grammar and the principle of science, that is to say, without logic.