If there could be a definitive book on marihuana, this would be it but as Mr. Grinspoon points out at the beginning of his overwhelming work of reasoned evaluation, ""the current state of knowledge"" of cannabis and its derivatives is insufficient: there has been a lack of research study, particularly dealing with human subjects, since the '40's and the only clear thing is that the law is ""inequitable,"" ""barbaric"" and ""counterproductive."" While he admits to no special pleading for or sanitizing of the drug, the end results of his findings all tend to prove its innocence -- i.e., re the escalation toward harder drugs, one phase under consideration, ""opiate use without a past history of marihuana is seven times likelier,"" Grinspoon discusses successively its old world history as well as that in the U.S. and Anslinger's ""superficial and hyperbolic"" resume of the dangers of the drug, an approach which would later be emulated by the A.M.A.; the plant itself and its worldwide varieties (it even has a bewildering capacity to change its sex); its chemistry and pharmacology; acute intoxication whether in the literary literature (Gamier, Baudelaire, etc.) or in actual life where person-to-person reactions are various and unpredictable. He also analyzes the motivation, or rather lack of motivation in the individual, which prompts heavier usage but one can turn off as easily as on (therefore it seems not to handicap automobile drivers, for instance); its injuriousness -- seemingly only in those with pre-existing personality problems (cf. Marin & Cohen); and its relation to crime and excess -- again a clearance since the diminution of inhibitions affects verbal rather than behavioral performance. Grinspoon closes with the manifest prejudice against the drug and the question of its legalization which he promotes. . . . A formidable and admirable work, with all the necessary apparatus.