In the previous chapter, we examined the evolutionary reasons that favored the emergence of symbolic thought. In this chapter, I address the problem of which cognitive capacities were necessary for symbolic thought to emerge from a background of iconic representations. Firstly, I discuss the relations and differences between symbols and indices. Secondly, I discuss the relations between icons and symbols, and, then, I turn to discuss the cognitive factors required for the emergence and usage of symbols. Specifically, I discuss the cognitive factors that enabled the move from iconic representations to symbolic representations. I am searching for a plausible sort of “cognitive revolution”, that is a set of processes in the mind, that allowed the move from iconic representations to symbols, and, in this sense, went beyond the cognitive capacities required for the employment of iconic representations. For example, iconic representations are not recursive, whereas advanced symbolic systems are recursive. It follows that agents that use recursive representational systems must have a cognitive capacity that the predecessors who could not use recursive representational systems did not have. Finally, I address the problem of whether H.E possessed some sort of language or protolanguage.