 Fourth, it is commonly presupposed that naturalistic analyses of non-natural, underived meanings will apply, in the first instance, to the contents of thought. The physical items “X” that are supposed to be bearers of causally determined content will, therefore, be something like the firings of a particular neuron or set of neurons. These contents of thoughts are said to be captured in what is sometimes called a “language of thought” or “mentalese.” The contents of items in natural languages, such as English, Japanese, and French, will then be given a separate analysis, presumably in terms of a naturalistic account of non-natural derived meanings. It is, of course, possible to suppose that it is natural language, or some other system of communication, that first develops content, which can then serve as a basis upon which to provide an account of mental content. Among the reasons that threaten this order of dependency is the fact that cognitive agents appear to have evolved before systems of communication. Another reason is that human infants at least appear to have some sophisticated cognitive capacities involving mental representation, before they speak or understand natural languages. Yet another reason is that, although some social animals may have systems of communication complex enough to support the genesis of mental content, other non-social cognizing animals may not.