The notion that history proceeds in (0) LINEARITY (LINEAR) from barbarism to refinement has exercised an almost hypnotic grip on Western thought since the 1ENLIGHTEN. Generations of philosophers took it for granted that each century would surpass the last, morally as well as materially, and treated the contrary view with a certain condescending 2SCEPTIC. The catastrophes of the twentieth century should have punctured that complacency, yet the underlying faith in the 3INEVITABLE of progress has proved remarkably resilient. A more 4RETROSPECT reading of the record suggests that advances in medicine, rights and prosperity have often been accompanied by regressions of comparable magnitude, and that the 5TRIUMPH narratives of national greatness usually involve considerable 6SIMPLE. The sober historian, drawing on a wider geographical and temporal canvas, offers 7CAUTION tales rather than whiggish reassurance, and counsels the kind of intellectual 8HUMBLE that hindsight so often makes difficult.