Fin-De-Siecle is Schorske's seminal work charting the crisis of liberalism in Vienna and the birth of modernism from the ashes of that crisis.
Schorske chronicles the failure of liberalism to secure the material security and social stability necessary to national viability largely as a failure of the irrational. To Schorske, liberalism is all about rationalism. So, he basically charts the reinventing of Viennese liberalism as a repudiation of irrationalism.
Thus, the modernist values characterized by the works of Gustav Mahler and Arnold Schoenberg (both composers), Oscar Kokoschka (artist), and Sigmund Freud (father of psychoanalysis) reinforces this new emergence of a movement largely concerned with an expressionist view of liberalism. Expressionism(in art and literature) is largely an effort to distance oneself from the religious definition of spirituality and discernment and the inadequacies of such a definition to reconcile the anxieties of modern life for the common man.
Schorske describes the first movement as defined by the emergence of Georg von Schönerer's Pan-German movement and Karl Lueger's Christian Socialism. Schonerer held largely anti-Semitic views in championing the cause of the downtrodden masses against the excesses of capitalism. Schonerer's anti-Semitism led him to characterize Jews as the epitome of capitalist degeneracy, his ideas influencing a young Adolph Hitler.
The second movement is characterized by the emergence of Freud's 'psychological man.' Freud's seminal work The Interpretation of Dreams sees the introduction of the theory of dreams as a vehicle for recognizing the latent desires inherent in all of us. Freud simply calls this the 'wish fulfillment' factor of dreams, where each individual unconsciously explores repressed desires in the safe recesses of sleep.
The third movement sees a newly confident expressionism encompassed by the works of Kokoschka (art), Schoenberg (composer), Gustav Klimt (artist). Expressionism is largely concerned with a brutal analysis of the realities of modern life. Expressionists believed that the old definition of morality (as defined by the restrictions of 19th century stability) must be replaced with new systems which better defined the collective needs of modern humanity. Ironically, the Nazi German regime presided over a strict censorship of expressionist art, deeming them 'degenerate art.'
Overall, Schorske's work is a monumental piece of literature which describes the crisis of Liberalism and the birth of modernism with thoughtful scholarship and intriguing implications for our future.
For a great summary of Schorske's important work, please refer to the excellent eNotes summary here.