Before you can intelligently debate the pros and cons of legalizing pot, you'll need to know a little background on the bud.

In the 1960s, if you knew whether or not someone had ever smoked marijuana, you could make a pretty intelligent guess about his or her political views. These days, marijuana isn't quite as potent a symbol of the cultural divide; still, for a big green bush, marijuana remains mighty controversial. Much of the recent controversy has surrounded laws passed in 1996 by voters in California and Arizona legalizing marijuana for certain medical conditions. But if you go back only a hundred years, and look at the public's attitude toward the weed back then, the smoke clears. For the several thousand years humans have been acquainted with marijuana, they have considered it one of the hardiest and most versatile plants around.

1. LEARN SOME BACKGROUND ON THE ISSUE

Marijuana, or Cannabis sativa, is a dioecious plant (which is a fancy way of saying it's a sexy plant; there are separate male and female plants, and they've got to get it on in the pistil and stamen scene), containing upwards of four hundred chemicals. The psychoactive agent, THC, or, for you chemistry savants, delta-9-tetrahydrocannabinol, is much more abundant in the female buds. THC is what makes you laugh uncontrollably at the lamest possible thing when you're stoned.

In colonial America, "hemp" was a major agricultural crop; both Washington and Jefferson raised it. Hemp was valuable because you could use its fibers for rope and canvas and its seeds for soap, lamp oil and birdseed. Preoccupied with finding practical uses for weed, people from temperate climates did not realize the great fun you could have simply by smoking it. Folk weren't so benighted in hot regions like India and North Africa. Here the plant fairly oozes with sticky resin, and is fit to be boiled for tea, ingested, and . . . you guessed it . . . smoked. Here also, perhaps under the psychoactive influence of the drug, they started giving it really cool names like dagga, ganja, bhang and hashish, from which we get the word "assassin."

Along with absinthe, hashish was de riguer for French artists and writers in the late 19th century. At the same time, physicians, who had been recommending tinctures of marijuana for pain relief, began switching to synthetic drugs marketed by a burgeoning pharmaceuticals industry. As the drug became associated with marginal groups - Mexican laborers, blacks, jazz musicians, prostitutes - many states started passing laws against it. In the 1930s, the Bureau of Narcotics (now the Drug Enforcement Agency) got interested in pot. This was the era of "reefer madness," when the government tried to convince the public that marijuana made you crazy, horny and violent, or some unwholesome combination of the three. Pot finally went underground with the passage of the Marijuana Tax Act in 1937, only to emerge thirty years later as the drug of choice of socially-aware, middle-class college students.

In the 1970s, larger segments of society were toking up. A number of states, among them California, recognized this and decriminalized possession of small amounts. However, the relaxation of America's marijuana laws was only temporary: Reagan's ascendancy to the top job in 1980 heralded a national shift to the right, and legislators responded with acts carrying harsher and harsher penalties for drug offenses. Under President Clinton, the "war on drugs" has continued to receive massive federal funding.

Americans are funny about marijuana: present them with a pile of facts showing that the enforcement effort is wasteful and ineffective and you'll be greeted with an angry glare. Simply put, a majority of Americans find marijuana morally offensive, although, if the studies are right, a third of them had to try it a few times before they could be sure.

Furthermore, most Americans, except maybe some in Idaho, aren't warm to the libertarian point of view, which goes something like this: "Where does the government get off telling me what I can and can't do with my own body? Humans have always used drugs, natural or otherwise, and it is paternalistic to tell us which ones are okay to use and which ones are not." A more nuanced offshoot of this school of thought suggests that the ultimate answer is to allow people to grow their own and use it themselves or give it away, but not to sell it.

Intelligent people can still disagree as to the health risks of chronic marijuana use. Pro-marijuana folk blame the government for this, saying the government only gives lip service to the need for further study of pot, as it will not freely release it to scientists to study.