A topic in the Open Knowledge Graph — a free, open map of 15,290 topics and the order to learn them in.
Wide content externalism holds that the content of a mental state is partly constituted by the individual's external environment and historical relations to it. Your thought 'water' refers to H₂O rather than XYZ because of your actual causal history with H₂O, not merely because of your intrinsic brain state.
Use Putnam's Twin Earth argument to motivate externalism. Examine how much of our conceptual scheme depends on our environmental and historical relations.
Your study of intentionality established that mental states have content — they are about things in the world. A belief isn't just a neural state; it represents something, and that representational property is what makes it the belief it is. Representationalism developed this further: mental states have their content in virtue of standing in the right representational relations. Now the crucial question arises: what determines what a mental state represents? The internalist answer, which might seem obvious, is that content is fixed by what's inside the head — the intrinsic physical or functional properties of your brain state. Wide content externalism denies this claim.
Hilary Putnam's Twin Earth thought experiment is the argument that changed the field. Imagine a planet physically identical to Earth in every respect, except that the liquid called "water" there is not H₂O but a different compound — call it XYZ — that looks, tastes, and behaves exactly like water. In 1750, before the discovery of molecular structure, an Earthling and their Twin Earth counterpart would be in identical brain states when they think "water." Yet, externalists argue, they mean different things: the Earthling means H₂O, the Twin-Earther means XYZ. The thought contents differ even though the inner states are identical. The slogan: "meanings just ain't in the head."
Your prerequisite on natural kind terms semantics explains why this follows. Terms like "water," "gold," and "tiger" refer to natural kinds — their reference is fixed by the actual nature of the stuff in the world, not by our descriptions or concepts of it. "Water is H₂O" was a scientific discovery, not a definition. Your concept "water" refers to H₂O because of your actual causal-historical connection to H₂O in your environment — the wells you drank from, the rivers you swam in, the molecules in your body. Twin Earth water, causally connected to XYZ, refers to XYZ. The environment, and your history with it, partly constitutes the content of your mental states.
The philosophical implications are significant. If content is wide (partly constituted by the environment), then two subjects can be in identical brain states while thinking different thoughts. This challenges the assumption that psychology should study only what is "in the head." It also raises questions about self-knowledge: if you can't know whether you're on Earth or Twin Earth just by introspection, you can't know with certainty what your own mental states are about. Externalism does not deny that there are intrinsic brain states — it denies that those intrinsic states alone fix representational content. The mind reaches into the world, and the world reaches back.
Topics in reflective domains aren't scored by quiz answers. Read, reflect, and mark when you've thought it through.