Causal Theory of Reference

Hello! Welcome to your next lesson.

In our last session, we saw how Saul Kripke dismantled the descriptivist theory of names. His modal, epistemic, and semantic arguments showed that a name's reference isn't determined by the descriptions a speaker has in their head. This brilliant critique, however, was purely negative. It left a crucial question unanswered: If descriptions don't fix reference, what does?

Today, we explore Kripke's positive answer. This lesson will focus on the causal-historical theory of reference. We'll see how this powerful idea explains the reference of proper names, and then how Kripke and Hilary Putnam extended it to explain the meaning of natural kind terms like 'water' and 'gold'. This directly addresses your learning outcome for this lesson and provides the positive account that Kripke's negative arguments demand.

1. The Causal-Historical Theory of Proper Names

Kripke's alternative picture is surprisingly intuitive. It suggests that our ability to talk about, say, Aristotle, doesn't rely on us knowing any unique facts about him. Instead, we are part of a long chain of communication that stretches back through history to the man himself.

The theory has two main components:

1. An Initial Baptism (or "Dubbing"): A name is given to an object or person. This can be done by pointing at the object (ostension) and saying, "This will be called 'Aristotle'," or via a description that fixes the reference, like "the first baby born in this hospital in 2024 will be named 'Alex'."
2. The Causal Chain: The name is then passed from speaker to speaker. Each subsequent speaker "borrows" their reference from the person they learned the name from. For the chain to work, each speaker must intend to use the name with the same reference as the person they heard it from.

To get a clear grasp of this, let's watch a short video that outlines the theory.

This theory beautifully explains the Gödel-Schmidt case from our last lesson. When we use the name 'Gödel', we refer to Gödel—the man who was originally baptized with that name—because we are part of a causal chain leading back to him. The fact that most of us associate the description "the man who proved the incompleteness of arithmetic" with the name is irrelevant to who the name actually refers to. Our use of the name is causally anchored to the man, not to the description.

For a more formal articulation, which your background in mathematics might lead you to appreciate, it's useful to distinguish between a theory of meaning (semantics) and a theory of how meaning gets fixed (metasemantics). The causal theory is a metasemantic theory.

This account introduces a key piece of terminology. The view that a name's meaning is simply its referent is called Millianism. The causal theory provides the story—the metasemantics—for how a name gets attached to its referent in the first place.

2. Extending the Theory to Natural Kinds

Kripke, along with philosopher Hilary Putnam, noticed that natural kind terms—terms for kinds found in nature like 'water', 'gold', 'tiger', or 'lemon'—behave a lot like proper names.

Consider the statement "Gold is the element with atomic number 79." This feels like a necessary truth, but it was an empirical discovery, known a posteriori. This parallels the "Hesperus is Phosphorus" case for proper names. Kripke and Putnam argued that natural kind terms are also rigid designators: 'gold' refers to the same substance in every possible world.

So, how can the causal theory apply to them? The model is analogous:

1. Initial Baptism: A kind is named by pointing to a sample. Someone points to a glass of clear liquid and says, "This stuff will be called 'water'."
2. Reference Fixing: Crucially, the reference of 'water' is fixed to be whatever has the same underlying essential structure as the stuff in that sample. The superficial properties (clear, tasteless, liquid at room temperature) are just how we identify samples; they don't define the term.
3. Causal Chain: The term 'water' is passed down through the linguistic community, intending to refer to that same kind. Science later discovers what that essential structure is—in this case, H₂O.

Let's watch a video that extends the causal theory from names to natural kinds.

The key takeaway here is that for natural kind terms, reference is fixed by an ostended sample and an implicit "same kind" relation. "Water" refers to anything that is the same kind of stuff as this (while pointing at a sample). Science then tells us that the "same kind" relation, in this case, is "having the molecular structure H₂O."

The SEP entry on Natural Kinds provides further detail on this extension.

This idea has a radical consequence: the meaning of our words is determined not by what's in our heads (our beliefs, descriptions, or "stereotypes"), but by the actual structure of the external world and our causal connection to it. This view is known as semantic externalism.

Conclusion

Today we have seen the positive side of Kripke's revolution in the philosophy of language. By replacing the descriptivist picture with a causal-historical one, he provided a more robust and intuitive account of how our words connect to the world.

Key Takeaways:

• The Causal-Historical Theory posits that reference is determined by a two-stage process: an initial baptism where a name is bestowed, and a causal chain of communication that passes the name down while preserving its original reference.
• This theory applies to proper names (referring to individuals like Aristotle) and was extended by Kripke and Putnam to natural kind terms (referring to kinds like gold).
• For natural kinds, the baptism involves ostending a sample, and the reference is fixed by the underlying essential structure of that sample, which science can then discover.
• This leads to semantic externalism: the meaning and reference of our terms depend on causal connections to the external world, not just on the concepts or descriptions in our heads.

Preview of the Next Lesson:

The conclusion that "meanings just ain't in the head" is one of the most significant shifts in 20th-century analytic philosophy. To drive this point home, Hilary Putnam devised one of the most famous and influential thought experiments in the field: Twin Earth. In our next lesson, we will analyze the Twin Earth argument in detail and explore its profound implications for semantic externalism.