Otto Neurath was one of the central figures in the Unity of Science movement in the twentieth century. We believe that reconsidering Neurath"s views on the possibility and the desirability of what he sometimes called a unitary science is not only historically interesting, but that it is also directly relevant to contemporary philosophy of science. Thanks, in large part to Quine"s influential promotion of some Neurathian themes, Neurath"s fallibilist view of science has played a central role in the formation of modern naturalism.