Should drugs be legalised?

Stoner's, junkies, dealers, whatever you call them, drug users and sellers are a part of life. From the man on the street, to those in high society, there are people that are affected by and dependent on, illicit drugs. The last Emperor of China, Puyi, was addicted to opium and prostitutes to such an extent, it brought about the end of the Qing dynasty. But would that have happened in a society where drugs are legalised and regulated? Would the mainstreaming of illicit drugs be a positive, or negative? As usual Dave and Garry give their robust opinions on the contentious idea of legalising drugs.