While purely causal theories of reference have provided a plausible account of the meanings of names and natural kind terms, they cannot handle vacuous theoretical terms. The causal homeostasis theory can but incurs other difficulties. Theories of reference that are intensional and not purely causal tend to be molecularist or holist. Holist theories threaten transtheoretic reference, whereas molecularist theories must supply a principled basis for selecting privileged meaning-determining relations between terms. The causal homeostasis theory is a two-factor (causal and intensional) molecularist theory, but it fails to provide such a principled basis and collapses into holism. A naturalistic, non-foundationalist holism that deploys strategies of intertheoretic reduction and co-evolutionary pluralism can, however, yield a credible version of transtheoretic reference.