Greek philosopher who began the search for a description of matter more than 2400 years ago. His theory was that matter could not divided into smaller pieces and eventually the smallest possible piece would be obtained. Named "Atomos", it meant that it could not be cut or divisible. These could infinite in number and capable of moving and joining together. They were made up of the same material's but in different shapes and sizes. However this theory was majorly ignored at the time due to the presence of other eminent philosophers who had more respectable theories such as the earth, fire, air and water approach to the nature of matter.