Scientific philosophy has been so closely linked with the doctrine of logical positivism that its earlier forms have dropped out of sight. The idea of a philosophy rigorously modeled on science has a long history. The purpose of this article is to examine how Abel Rey, before the emergence of the Vienna Circle, brought together various earlier attempts to formulate a philosophy based on scientific research. Moreover, Rey edited a special issue on psychology with the contribution of several members of the Circle. This collective work spurred a dialogue touching on certain fundamental orientations of philosophy of science.