Toynbee dated the postmodern age from industrialism breaking the bounds of nationality.

Evidence

In the first volume of his Study of History, also published in 1934, Arnold Toynbee argued that the concurrence of two powerful forces, Industrialism and Nationalism, had shaped the recent history of the West. Since the last quarter of the nineteenth century, however, they had entered into destructive contradiction with each other, as the international scale of industry burst the bounds of nationality, yet the contagion of nationalism itself spread downwards into ever smaller and less viable ethnic communities. The Great War had sprung from the conflict between these trends, making it unmistakeably clear that an age had opened in which national power could no longer be self-sufficient. It was the duty of historians to find a new horizon appropriate to the epoch, which could only be found at the higher level of civilizations, beyond the outworn category of nation-states. — Perry Anderson, The Origins of Postmodernity, 12

Categorization

• DEFINE: Explains Toynbee’s causal logic for his periodization: the contradictory triumph of Industrialism over Nationalism is what opens the postmodern age.
• XREF: connects to: Toynbee’s postmodern age begins with the crash of bourgeois complacency in 1914. — Perry Anderson, The Origins of Postmodernity, 14; Toynbee introduced ‘post-modern’ as an epochal category, not an aesthetic one. — Perry Anderson, The Origins of Postmodernity, 12; Expansion of capital and demography dilutes inherited culture into a lower postmodern level. — Perry Anderson, The Origins of Postmodernity, 165 (+1 more)

Broader Connections

• Toynbee introduced ‘post-modern’ as an epochal category, not an aesthetic one. #expands (0.95) — Perry Anderson, The Origins of Postmodernity, 12
• Toynbee’s postmodern age begins with the crash of bourgeois complacency in 1914. #qualifies (0.85) — Perry Anderson, The Origins of Postmodernity, 14
• Postmodernism’s case rests on a radical break dated to 1960 #contradicts (0.85) — Fredric Jameson, Postmodernism, or, The Cultural Logic…, 35
• Expansion of capital and demography dilutes inherited culture into a lower postmodern level. #expands (0.80) — Perry Anderson, The Origins of Postmodernity, 165