my peers, lately, have found companionship through means of intoxication—it makes them sociable. I, however, cannot force myself to use drugs to cheat on my loneliness—it is all that I have—and when the drugs and alcohol dissipate, will be all that my peers have as well.  franz kafka
 
I don't take drugs as an escape trick, like some cheap magician on a cruise ship.  I take drugs to find gold, like a greedy prospector in the backcountry.  There are those who take drugs to be cool and those who take drugs to expand.  I am not James Dean.  I'm a balloon.  And god has a mouth on my hole.  And is blowing.  And filling me up.  And filling me up.  One day I will explode.  And then I will be free. Robert sedlock
 
The basic thing nobody asks is why do people take drugs of any sort? Why do we have these accessories to normal living to live? Is there something wrong with society that’s making us so pressurized that we cannot live without guarding ourselves against it? John lennon
 
I don’t do drugs, I am drugs. Salvador dali

 
From Sadie Plant’s Writing on Drugs:

 
Private Eyes
 
I began to write, almost without realizing it , without thinking, busy transmitting these words I don’t recognize, although they are highly significant: “Too much! Too much! You’re giving me too much!”
Henri Michaux, Darkness Moves
 
A vast literature on drugs has assembled itself in the lat two hundred years. It begins with the late eightennth century’s explorations of opium, wends its way through cannabis, coca, and cocaine, and later finds itself entangled with a wide variety of plant hallucinogens and synthetic drugs.           

Like their writings and their writers, these substances could hardly be more diverse. Some of them are ancient, others very new. Some are synthesized in laboratories, and some grow wild. Some are widely used as medicines, a few are fatal in large doses, some have no toxicity at all. In the twentieth century, the vast majority of these substances find themselves controlled by some of the world’s oldest international agreements and its most extensive national laws. But they do have their own common ground as well. Whether they are organic or synthetic, old or new, stimulating, narcotic, or hallucinogenic, all these drugs have some specific psychoactive effect: they all shift perceptions, affect moods, change behaviour, and alter states of mind. And all of them have exerted an influence that extends far beyond their users. The laws and wars on drugs are symptomatic of the ways in which these substances provoke the same extreme reactions in cultures, economies – social, political, legal – and even military systems. Their effects on the human nervous system seem to repeat themselves wherever they occur. When drugs change their users, they change everything.