Cézanne often painted the same subject multiple times, especially still lives of apples and landscapes.
He did this because he wanted to experiment with form. The subject was not important to him. He was attempting to capture the range of colours and possibities available from every day objects. He used the colours as a type of perspective, the strength of the colour reflecting the depth.
Cézanne also painted the landscape (Mt. Saint-Victoire) hundreds of times over 20 years.
Each time he painted it, it was different. This is not just because of the change that time inflicted on the landscape but also because of the changes in the artist himself. The more he painted it, the more abstract it became, until it properly reflected his world view. Cézanne was also unafraid to include references to industry, i.e. the railway bridge. In fact, many impressionists were fascinated by the idea of industry and progress and trains, stations and railway bridges often featured in their paintings. The station was viewed as a gateway to the modern world while the bridge was a sign of progress and was often painted in use or at a dynamic angle to convey movement.
Cézanne rethought painting: he painted the same thing over and over again to show multiple possible perspectives. This idea is further developed in cubism where they try to show all these perspectives and dimensions at the same time. In some ways, this is inspired by film, as the concept of capturing a moving image is reflected in their paintings. They attempt to show all these possible angles in one painting.
The idea of movement in painting was carried even further in the idea of futurism, a style of painting inspired by film which attempted to capture a sequence of perspectives. They were very focused on 'dynamism' and the idea of the world in continual movement. They also reinvented poetry as they began to question why words should have to go in straight lines and be ordered. One of their chief subjects was war, as they liked to focus on the speed and action.
The leader of the movement was in fact a fascist and supporter of Mussolini. At this point, art began to become more political and the many avant garde movements that developed in the 20th century often had political manifestos and aims.
