Modern art emerged between 1870-1970 and used new materials and techniques like pointillism. Artists developed theories that art should reflect the perceived world. Neo-classicism focused on Greek/Roman styles and humanism over religion. Romanticism contrasted classicism and used emotion to inspire works. Realism believed truth has its own beauty and represented social issues. Impressionism focused on light, basic shapes, and nature's influence. Post-Impressionism became more symbolic and rejected realistic nature inspiration.