A second option is to argue that genes and other biological structures literally carry semantic information, and their informational character explains the distinctive role of these structures in biological processes. If we think of genes or cells as literally carrying semantic information, our problem changes; who or what could count as composing or reading these messages? Paradigm cases of structures with semantic information—pictures, sentences, programs—are built by the thought and action of intelligent agents. So we need to show how genes and cells—neither intelligent systems themselves nor the products of intelligence—can carry semantic information, and how the information they carry explains their biological role. We need some kind of reductive explanation of semantic information (arguably, we need this to understand cognition, too). One place we might look for such an analysis is naturalistic philosophy of mind.