Commentary: the search for a unified field theory

[First paragraph] The conference sessions of which the foregoing articles are the fruit were dedicated to the discussion of the interrelationship of changing labour systems and technologies in Caribbean sugar plantations between 1750 and 1900. What made the exercise frustrating and incomplete as well as challenging and important was that it clearly involved many more variables besides those of labour and technology. However widely labour and technology are defined, at least five other related and intertwined factors have to be considered: the availability and suitability of land; the supply of capital; the access to markets and market prices; management strategies, attitudes and personnel; and finally, changing economie policies – specifically those designed to speed the transition from narrow mercantilist units to a world-wide "free trade" system.