In the generation between the Revolutions of 1793 and 1830, the community of science and technology outgrew the posture of the Enlightenment and assumed the stance of the nineteenth century. The old rationale of Condillac and the associationist psychology developed into that of Comte and positivism, which would know in order to predict and predict in order to control. Condorcet, last of the philosophes, left the testament of the eighteenth century to appear in 1795 after his death—Sketch for a Historical Picture of the Progress of the Human Mind. In that moving little book, science figures as the bearer of progress. It is the instrument which educates the human understanding in the order of nature. But the revolutionary generation was more messianic than naturalistic, and it transmuted this benign educational mission into something closer to engineering—civil engineering, social engineering, and perhaps the engineering of humanity itself. The Encyclopedists had already prided themselves on freeing science from metaphysics. Now the positivists would consummate the emancipation by liberating science even from ontology and, indeed, from every pretence to lay hold on a reality beyond observation, experience and act. Comte wished to abandon absolute in favour of relative statements. And for this reason, he looked to human history rather than to some outer reality as the repository of experience. In his philosophy, rationalism turned attention to historical thinking, which had hitherto been the resort of romantics hostile to exact science. Man in history replaced matter in motion as the natural process par excellence, and science, rising in history, served it also as dynamic motor, the factor which made all the difference between one age and another, and which, graduating into knowledge of its own methods, held the promise of regeneration.