Hindu beliefs about appropriate use of cannabis illustrate the capacity of cultural systems to order and direct the course of complex phenomenal events. Cannabis manifests diverse and contradictory effects. These depend not only on dose, frequency and route of administration, but also on subjective and cultural contexts (e.g., Pihl, Shea & Costa 1979). It may very well be that the contradictory results of modern research investigations on cannabis stem from the intricacy of these interactions. Given the current state of the art, paradigms of research methodology may very well be inadequate to develop an understanding of such a paradoxical drug. The Hindu cultural system, on the other hand, accommodates the ambiguities of cannabis through its own complex nature. It provides diverse niches through which antithetical effects of the drug are expressed. Cannabis is said to both interfere with motivation to work and facilitate it. A closer examination reveals that these actions are probably related to the way in which this motivation toward action is defined, and the level of use of the drug. While cannabis appears to interfere with execution of highly complex tasks and the long-range planning that accompanies them, it may facilitate concentrated focus on repetitive endeavors. In some commonsense way, it may be quite simply that it changes a user's sense of time and the span of the present as well as the sense of relative importance of present and future. So long as an individual is under the influence of this effect (and living in the context that s/he has structured as a result of it), the urgency of accomplishment in the Western sense is diminished. The Hindu belief system accommodates this by prescribing use in such a way that this effect becomes beneficial. A key factor is that low potency preparations (bhang, thandai) are available. It allows individuals with complex life tasks, goals and obligations to indulge in moderation. The drug is also taken in a ritualized context, facilitating concentration and relaxation. It is taken at times, such as in the evening or on holidays, in which focus on the immediate present is a welcome change. Use of the more potent preparations (ganja, charas) is not condoned for this group. Above all, moderation is enjoined and popular folk belief warns of the potential problems of excess. Ganja and charas are regarded more ambivalently as poisons or semipoisons.(ABSTRACT TRUNCATED AT 400 WORDS)