  Although the Extensional model can be developed in different ways, much of what these variants have in common can be brought out by looking at how proponents of the approach construe individual specious presents. For present purposes, so as to bring the essentials to the fore, it will be useful to focus on a very simple instance. Figure 5 depicts a single specious present with a very simple content: ‘C’ and ‘D’ are each brief tones, which are heard and experienced in succession; this specious present contains nothing but these two tones.