Although Hobbes's intellectual interests shifted towards the physical sciences in his middle years, I have been arguing that his later writings continue to bear many traces of his earlier engagement with the humanistic disciplines. The present chapter is concerned with the most visible of these traces: his enduring interest in the visual representation of his political ideas, and his consequent inclusion of emblematic frontispieces in his works of civil science as well as in his translations of classical texts.

To explain this commitment, we first need to return to the rhetorical tradition in which Hobbes was nurtured as a student at the University of Oxford in the opening years of the seventeenth century. As I showed in chapter 1, the avowed aim of the classical rhetoricians was to offer instructions on how to write and speak in the most ‘winning’ style. One of the most potent means of persuading an audience to adopt your point of view will always be to add pathos to logos, to arouse the emotions of your hearers in such a way as to shift them round to your side. The figure of Antonius puts the point with characteristic frankness in Cicero's De oratore, arguing that ‘you must try to move them so that they become ruled not by deliberation and judgment but rather by sheer impetus and perturbation of mind.’

As to how this can be done, the rhetoricians have a number of practical suggestions to make. One of the most important is that you must learn to present your case with so much vividness and immediacy that your audience comes to ‘see’ what you are trying to describe. This is the quality described by Quintilian as enargeia, the capacity we display ‘when we not only say what is true but in a certain sense reveal it to the sight’. If we can learn to speak with this degree of vividness, we can present our hearers with ‘an image of an entire scene that is somehow painted in words’. The orator's power to persuade is thus held to depend in large part on the ability to appeal, in Quintilian's phrase, ‘to the eyes of the mind.’