It is tempting to think about mental representations of the world by analogy to the linguistic representations that we use to communicate with each other in speech and writing. The philosopher Jerry Fodor claimed that there is a language of thought with the same kinds of structures as a natural language such as English or Chinese. Many contemporary philosophers assume that knowing is a propositional attitude, which is a relation between a person and some kind of sentencelike entity. But understanding minds as brains requires us to take a much broader view of representations, with linguistic structures such as sentences serving as only one way that the brain knows the world. You do not have to be a linguistically sophisticated adult human to have knowledge of objects. Other
language-limited animals such as rats and lizards have perceptions too, as do human infants well before they have learned to talk. In the previous chapter, I described how we can think of brains as functioning by using patterns of activity of firing by interconnected neurons. Now I will go into a bit more detail about how visual perception of objects works in the brain.