Abstract: Several aims were taken into account when writing this article. First of all, it was my intention to reveal and highlight the personality and the achievements of the Nobel Prize Laureates in Economics, awarded by the Royal Bank of Sweden (Sveriges Rjksbank). And, one of these important economists, is Sir William Arthur Lewis (1915-1991), iconic reprezentant of the Winward Isles (West Caribbean Islands) and, thus, we make the transition to a second aim, that one of the 70th anniversary of the publication of Lewis’ theory of resistance, The Theory of Economic Growth. The third aim, factually that aim which re-unite the other two, is to present St. Lucia’s becoming, as a model of passing from mono-culture agriculture to a developing economy, with outstanding services on top. Finally, we try and succeed, in a manner, to look to the Lewis theory from another: angle, that one of extension the development on agricultural domains (vegetables, livestock..), in a niche mode, fact which ensure the development of the respective zone/region and, by consequence, the development of the entire economy in discussion. We presented examples, from many others, of this passage from a subsistence agriculture and an underdeveloped economy, nowadays supported by the new digital technologies, to the next stage of industrialized and diversified economies, that the stage of developing economies. In sum, it is a permanent movement towards development, good living standards, benefit/profit for all.