Dear Ms Sadia! please be cool minded, I am not trying to let you down, but trying to convey the exact meanings but you are still.....missing because:
The writer is including Democritus in perilous company(dangerous people) who had started futile discussion about reality and external world and this useless discussion remained alive till the medieval times.
By the way, i think you have literary back ground and thanks for pointing out my mistakes i.e. "meanigs, plz dont and comprehnding" In this connection i would say that it was just net speak vocabulary.