A causal theory of reference or historical chain theory of reference is a theory of how terms acquire specific referents based on evidence. Such theories have been used to describe many referring terms, particularly logical terms, proper names, and natural kind terms. In the case of names, for example, a causal theory of reference typically involves the following claims:
a name's referent is fixed by an original act of naming (also called a "dubbing" or, by Saul Kripke, an "initial baptism"), whereupon the name becomes a rigid designator of that object.
later uses of the name succeed in referring to the referent by being linked to that original act via a causal chain.
Weaker versions of the position (perhaps not properly called "causal theories"), claim merely that, in many cases, events in the causal history of a speaker's use of the term, including when the term was first acquired, must be considered to correctly assign references to the speaker's words.
Causal theories of names became popular during the 1970s, under the influence of work by Saul Kripke and Keith Donnellan. Kripke and Hilary Putnam also defended an analogous causal account of natural kind terms.
In lectures later published as Naming and Necessity, Kripke provided a rough outline of his causal theory of reference for names. Although he refused to explicitly endorse such a theory, he indicated that such an approach was far more promising than the then-popular descriptive theory of names introduced by Russell, according to which names are in fact disguised definite descriptions. Kripke argued that in order to use a name successfully to refer to something, you do not have to be acquainted with a uniquely identifying description of that thing. Rather, your use of the name need only be caused (in an appropriate way) by the naming of that thing.
Such a causal process might proceed as follows: the parents of a newborn baby name it, pointing to the child and saying "we'll call her 'Jane'." Henceforth everyone calls her 'Jane'. With that act, the parents give the girl her name.