Realism vs idealism

Descartes talked about two realms, a realm of spirit and a realm of matter. A major problem was how it was possible for the spirit to set matter in motion, because the spirit had no material aspects and matter no spiritual aspects. Later philosophers therefore distanced themselves from that Cartesian dualism and limited themselves to one realm, which encompassed both thought and movement. But to this day there is disagreement about what that kingdom actually entails.Nowadays physics has penetrated deeply into matter. It seems that she understands well the domain of the smallest parts of matter, the quarks and the electrons. And also for the domain of the largest dimensions, that of the universe, there are theories that very accurately describe what happens there. There is complete agreement about the content of those theories. But what exactly these theories mean is still hotly debated. On the one hand there are the platonists, or realists, who assume that these theories describe reality as it actually is, and on the other hand there are the idealists or positivists, who say that these theories are no more than models that are equally can easily be replaced by other models.