Leucippus or Leukippos -LRB- MISC@1 : , first half of 5th century BC -RRB- was the first MISC@1 to develop the theory of atomism -- the idea that everything is composed entirely of various imperishable , indivisible elements called atoms -- which was elaborated in far greater detail by his pupil and successor , MISC@2 .

Leucippus or Leukippos -LRB- MISC@1 : , first half of 5th century BC -RRB- was among the earliest philosophers of atomism , the idea that everything is made up of many imperishable , indivisible elements called atoms .
