 A nice to way to consider this is in terms of Quine’s (1951) distinction between the “ontology” and the “ideology” of a scientific theory, where the ideology of a theory consists of the ideas that can be expressed in that theory. Ideological economy is then a measure of the economy of primitive undefined statements employed to reproduce this ideology. The claim here would then be that the ideology of symmetric causal influences is more economical than rejecting a classical ontology. Thus in so far as quantum mechanics is telling us something profound about the fundamental nature of reality, the hypothesis of retrocausality shows that the lesson of quantum mechanics is not necessarily that the quantum ontology can no longer be classical. Some might see this as a virtue of retrocausal approaches. (Although the Shrapnel-Costa no-go theorem reviewed in  §7.3  significantly jeopardizes this view.)