 To take the simplest example, the form of our subject-predicate thoughts corresponds perfectly to the structure of object-property facts. If there is an explanation of this correspondence to be given it seems it could go in one of three ways: either the form of thought explains the structure of reality (a form of idealism), or the other way round (a form of realism), or maybe there is a common explanation of why there is a correspondence between them, for example on a form of theism where God guarantees a match.