In the late 18th century, a poetic, artistic and cultural period arose called the Romantic period. It is "Romantic" because it was an attempt to revive the perceived glories of ancient Rome and classical Greece: beautiful architecture, an emphasis on beauty and love, an desire to get away from industrialization and elevate the human spirit with beauty. To the Romantic, life was beautiful and innocent, just so long as we didn't succumb to the inhuman advances of technology and industrialization. Humans were essentially good, if often tragic, and beauty was always to be striven for.
Later generations would come to think of the Romantic period as being somewhat naive. Human nature was tragic, and people were often evil. Everything we were taught about the goodness of human nature and the "we're all in this together" attitude came crashing down in WW1.
WW1 was so horrific; 20+ million dead, cities and towns destroyed; lives ruined forever; tens of thousands of soldiers returning home maimed, psychologically destroyed, and then totally forgotten by their own governments. Meanwhile, the generals and the politicians seemed to be doing just fine, and getting richer at the expense of the common people.
Trust in institutions and human agendas was lost. Life was seen as bleak; the "fairy tales" of the Romantic period were dismissed.
You can clearly see this attitude in Yeats' "The Second Coming" (1919, as the war ended) which we started the term with. Pay attention to the language of the poem's first stanza:
Turning and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.
What do you think?