"Drugs" is a blanket label given to various substances in our society which the people in control of our lives want us to think are bad while the good "drugs" (i.e. medicine) can be given to children (Ritalin, Prozac, etc.)
Two of the most dangerous drugs, which cause more deaths per year than all the illegals combined, alcohol and tobacco, are legal because our government makes money from their sale. (Sickness and death are also BIG BUSINESS so that is another reason for their legality.)
Substances which cause a person to question the power structures which attempt to control our lives and help free us from it are demonized and criminalized...such as Cannabis, LSD, Peyote and other sacred substances.
Seriously, look at the societies/cultures who hold those things sacred vs. the war-mongering, consumerist culture which absolutely hates and demonizes them.
And yes, as the above poster stated, read erowid.org and any books on sacred plants and Shamanism. You'll be glad you did.