 However, the response to this is that circularity is only a problem if the conceptions are interpreted as providing a reductive analysis of the notion of the physical. But there is no reason why they should be interpreted in that way. After all, we have many concepts that we understand without knowing how to analyze (cf. Lewis 1970). So there seems no reason to suppose that either the theory or object conception is providing anything else but a way of understanding the notion of the physical.