Why do cultures depend so much on mythical illusions to the past? Could the bicycle chained to the gate next door be a work of art? How do human beings really think, when they are not speaking? How do high and low culture relate to one another? Why do we need the 'progressive' and the 'new'? In this *Very Short Introduction* Christopher Butler looks at the many innovations created by Modernist thinkers and artists, showing how powerful ideas and formal experiment have produced the music, painting, and literature which has informed all aspects of 20th and 21st century life.