The ArgumentJacob de Castro Sarmento was a descendent of New Christians in Portugal who made his way to London in the early eighteenth century. There he professed Judaism openly, but he also advanced his scientific and medical pursuits, becoming particularly enamored of the Newtonian world view. This paper argues that Sarmento's attachment to Judaism was essentially a function of his personal relationship with Hakham David Nieto, and that Sarmento's Judaism was never really the full synthesis of scientific outlook and Jewish (...) theology toward which Nieto pushed him. Rather, after Nieto's death Sarmento identified himself with scientific Newtonianism increasingly openly, while his religious identitly waned. Apparently he found science a more useful outlook in approaching the world, as did many Newtonians of that generation. (shrink)