Preliminary Discourse to the Encyclopedia of Diderot

The Encyclopedia of Diderot and d'Alembert, ancestor of all the others, was an attempt to arrange and systematize the knowledge developed in a scattered and fragmentary manner, on the ruins of the scholastic philosophy and the medieval encyclopedism. D'Alembert wrote a preliminary discourse as justification of the work plan. The Encyclopedia suggested a genetic order of the knowledge, decided on the model of the Locke's empiricism, and followed a classification of the sciences, founded on the Bacon's Knowledge Tree (Memory/History, Reason/Philosophy and Imagination/Poetry). The work was also a "reasoned dictionary of sciences, arts and trades" as it explained the general principles of every science and arts, both liberal and mechanics, and their most remarkable details. The part of the Discourse that perhaps the reader will appreciate more, concerns the history of the progress of human thought: here the science is considered in the prospect of the modern civilization's making and triumph. Of particulat interest is the passage where D'Alembert honours Bacon and Descartes as forerunners of Enlightenment's Age and prophets of the intellectual freedom. The Encyclopedia offered to the middle class a new cultural model, of laical approach, rationally determined, bound to experience and turned to real life. The Enlightenment's faith in reason/rationality and progress fed on revolutionary conquests of rising middle class ( even Marx and Engels had words of admiration for the bourgeois enterprise).