This paper uses research findings and interpretive reasoning to challenge the claims that marijuana causes brain damage, harms the reproductive system, suppresses the immune system, "flattens" brain waves, impairs short-term memory, and lingers in the body like DDT. It also challenges the comparative claim that marijuana is "much more dangerous than tobacco," by claiming that "smoked marijuana contains about the same amount of carcinogens as does an equivalent amount of tobacco" and that "a heavy tobacco smoker consumes much more tobacco than a heavy marijuana smoker consumes marijuana." In addition, this report challenges the claim that marijuana is more potent today than in the past, and it criticizes as misleading the statement that there are over a thousand chemicals in marijuana smoke. Although acknowledging the truth of this statement, it compares this finding with the fact that roasted coffee has "over 800 volatile chemicals," of which only 21 have been tested on animals, with 16 of these causing cancer in rodents. Finally, the paper challenges the claim that should marijuana become legal, it would "cause carnage on the highways." It argues that although marijuana, when used to intoxication, does impair performance in a manner similar to alcohol, studies of the effect of marijuana on the automobile accident rate suggest that it poses less of a hazard than alcohol. 12 references