While Romanticism - set in the context of the American revolution - broke out of the gates at a run, and tended to affirm individual agency, Modernism - set in the context of the rise of the professional class and of proletarian political consciousness in the 2nd half of the 19th century, and especially after the horror of WWI - tended to doubt individual agency. Modernism questions, underscores a multiplicity of possibilities, and centres on the individual as a mere component within an atomised and politically polarised community. It doesn't say 'This is what I believe in' but, rather, asks 'What is left to believe in'. These questions had already started to be asked by the late Romantics - Flaubert, Whitman, Melville, Baudelaire - in the 1850s, at the time proletarian political organisation started to solidify. In their amazing works, the late Romantics signalled formally a capacity for agency - the works were strong - while simultaneously signalling doubt about the ability of the individual to find agency in the world. Theirs was the final flowering before the appearance of the two-stream culture industry - popular culture and "high" culture - that still exists today.
The bourgeois novel had started to appear over 100 years earlier, however, as is seen in Defoe's Robinson Crusoe, which sublimates industry and prudence. But what makes the 1850s different is the awareness of the death of God. Instead of divine certainties that could be used to justify individual action, the individual was forced to make sense of his or her place in the world in the absence of a loving and all-knowing deity. The 1850s also saw the appearance of the first "art movement", in the Pre-Raphaelites, a bunch of idealistic and progressive young men who placed a label on their aesthetic choices as a rebuke to bourgeois consumerism, and as a protest against the evils of rapid industrialisation: alcohol, unemployment, poverty, starvation, homelessness.
But what values could the elites impose on the proletariat in order to counter these evils without damaging their own position? Through high culture the elites invented the literature of the common man as a kind of rebuke to laziness and dissolution, while they supplied the proletariat with a popular culture that was inferior and divorced from the engine of aesthetic innovation. So they continued to feed the proles junk food while ignoring the messages the cultural elites injected into the high-culture products they celebrated and used to impose their kind of order on the community: an aesthetic order only they bothered to understand as a correlate of the economic order only they could control. And while the Marxist dialectic focused insistently on the cash-labour nexus, no alternative kind of way of living was proposed. Instead, the cultural elites expressed their despair by retreating into ironic distance, all the while the gap between high and popular culture has widened more and more; the contemporary culture industry exploits these gaps by vigorously atomising the community along lines of taste and genre.
Pockets of affirmation have appeared from time to time, such as with the Beats in the US in the 1950s, but these are quickly stigmatised for the benefit of the proletariat, by the elites, as destructive, while other parts of the elite appropriate them for their own use. Consequently, we are left with the irony of the atomised man alongside the mindlessness of popular culture: high and low never touching, existing on parallel tangents that pass through the domain of capital like twin rivers filled with the intoxicating elixirs people in the community crave to fend off the despair they feel due to their frustrating lives of work and unceasing economic obligation.
The last decade when the individual stood a chance against the power of innovation, and the market forces that feed off it, was the 1850s. Since that time, artistic innovation has been sundered from the culture of the people and purchased by the elite, resulting in the death of the individual. Melville, Flaubert and Whitman were the last of their kind, and the first to describe the horrors of the atomised society; with them died the flame of self-determination, and from that point in time the hegemony of the common man has gained traction. La revolution s'enfuit!