Dimensions of meaning associated with social differentiation among Melanesian peasant producers are explored in this study of customary land tenure and copra production in Longana, Aoba Island, Vanuatu. The notion of "customary illusions" --mystifications experienced as true --is developed to highlight suppositions, expectations and ideals formed in association with traditional land tenure and production for the market. My thesis is that these illusions represent ambiguous but meaningful fragments of complex reality. I use customary illusions as a relativistic device to focus on the whole of the problem of understanding Longanan peasant cash-cropping. The holistic approach I follow interrelates phenomenology, political economy and empiricism as complementary lenses for refracting meaning. The dissertation is based on twenty-eight months field research in 1978-1979 and 1969-1971. It begins with examination of consequences of the colonial history of Vanuatu as an Anglo-French Condominium for retention of customary land tenure and adoption of copra as a peasant cash-crop. I explore ni-Vanuatu illusions of independence amidst dependence and of inalienability of land amidst its alienation as products of the colonial experience. Next, the flexibility of traditional land tenure is investigated phenomenologically through the ambiguity of illusions linked with Longanans' experience of place. This flexibility is both an asset and a liability, ensuring that no one is landless but also allowing 5% of the landholders to control 31% of the plantation land. Inequality arising through land tenure flexibility represents differentiation within the peasantry as a class. Empirical analysis of plantation land distribution and copra sales suggests consequences of this inequality with particular attention to a class category of "big peasants," relatively weal thy, large landholders. Risks and costs that the copra market imposes constrain all producers' agricultural decisions so that, for example, they do not increase production in response to rising prices. Yet, through bargaining with buyers over terms other than prices, Longanans assert some control over market exchanges and affirm their own illusory independence. In sum, the dissertation seeks to enrich understanding of peasant producers' behaviour by analyzing the meaningful ambiguity of our illusions about them, and theirs about themselves. / Thesis / Doctor of Philosophy (PhD)