A number of recent objections to physicalism are based on the apparent gap between physical knowledge and phenomenal knowledge. In response, some physicalists accept the epistemic gap, but deny the inference from the epistemic gap to a metaphysical gap. One popular strategy is to argue that there is something unique about our phenomenal concepts, the concepts that we use to think about our phenomenal states in terms of their subjective character, that explains the apparent gap. I develop a version of this strategy.

Specifically, I argue that phenomenal-physical identities are necessarily true. These identities only seem contingent due to peculiarities of our phenomenal concepts. Phenomenal concepts have a unique connection to their referents; they are “self-presenting” concepts, which include their referents as components of the concepts themselves. Regardless of how we conceptualize the world, a phenomenal concept will always refer to the phenomenal state. But this is not true of non-phenomenal concepts, even concepts like ‘H ₂O’ that seem to get at the essence of their referents. There is always an element of contingency in the connection between a non-phenomenal concept and its referent.

When we consider an identity between a phenomenal concept and a non-phenomenal concept, like ‘pain = the firing of p-neurons’, the more intimate connection between the phenomenal concept and its referent generates the intuition that the two concepts could come apart. This is true in a sense. If we were to adopt conceptualize things differently, the physical concept might not refer to the same state. For example, if we were to adopt a different theory of neuroscience, we might not conceptualize the firing of p-neurons as ‘the firing of p-neurons’. Phenomenal concepts, on the other hand, will always pick out the same referents, regardless of how we represent the world. For this reason, the concepts ‘pain’ and ‘the firing of p-neurons’ do come apart, but not in a sense that makes trouble for physicalism. What is possible is not a world in which pain isn’t identical to the firing of p-neurons, but only a world in which pain isn’t conceptualized as the firing of p-neurons.