 One strand of representationalism, endorsed by Fodor, takes mental representations to be sentences in an internal language of thought. To get a sense of what this view amounts to, it is helpful to start with an analogy. Computers are sometimes characterized as operating by manipulating sentences in “machine language” in accordance with certain rules. Consider a simplified description of what happens as one enters numbers into a spreadsheet. Inputs from the keyboard cause the computer, depending on the programs it is running and its internal state, to instantiate or “token” a sentence (in machine language) with the content (translated into English) of, for example, “numerical value 4 in cell A1”. In accordance with certain rules, the machine then displays the shape “4” in a certain location on the monitor, and perhaps, if it is implementing the rule “the values of column B are to be twice the values of column A”, it tokens the sentence “numerical value 8 in cell B1” and displays the shape “8” in another location on the monitor. If we someday construct a robot whose behavior resembles that of a human being, we might imagine it to operate along broadly the lines described above—that is, by manipulating machine-language sentences in accordance with rules, in connection with various potential inputs and outputs. Such a robot might somewhere store the machine-language sentence whose English translation is “the chemical formula for water is H2O”. We might suppose this robot is able to act as does a human who possesses this belief because it is disposed to access this sentence appropriately on relevant occasions: When asked “of what chemical elements is water compounded?”, the robot accesses the water sentence and manipulates it and other relevant sentences in such a way that it produces an appropriate response.