The development of art was a very important one for the course of human history. The ability to spend time and energy, then focus it on something other than surviving was a huge step forward for early humans. Ever since then, art has become an integral part of the human existence, and its importance and use has changed over the course of history. Historians and archaeologists have speculated that the earliest forms of art served religious purposes. This would become one of the key interactions between humans and art, which continues to this very day. It was not until later that art became important simply for enjoyment, with common objects taking on aesthetic appeal. After this advancement it was again some time before humans started to use art to portray the world around them as realistically as possible. There has always been a struggle between the ideal world that we dream of, the the reality that surrounds us, and art allows people to blur the line between truth and fiction. Soon enough art became an important part of science as those interested in the natural world around them desired to share their findings with others. This created a separation between art used for religious purposes, art used for aesthetic purposes, and art used for objective purposes.