Swift specialised in playing with distinctions between reason and unreason. This chapter focuses on two major works, A Tale of a Tub (1704) and Gulliver’s Travels (1726), in which Swift’s blurs the line between reason and unreason: firstly in ‘A Digression concerning the Original, the Use and Improvement of Madness in a Commonwealth’, and secondly in Gulliver’s fourth voyage to the Yahoos. Swift repeatedly engages in a sleight of hand, obliging readers to appreciate the ease with which reason can slip into madness. But in the voyage to the Yahoos, this chapter argues, readers find Gulliver’s self-loathing and misanthropy to be a step too far. Swift’s skill is to make his reader question their own perspectives and their own balance between reason and unreason.

Mental illness is not strictly divisible from physical for much of the long eighteenth century: many mental disorders were thought to originate from physical causes and were treated by similar methods. But this category of disease had an enormous influence on literary productions throughout the period. In the early years, in Swift, for example, and in Pope and in adaptations of Shakespeare, being mad, or eccentric, tended to figure largely, while after the rise of the novel, and of sensibility in particular, the figure of the madman, and especially madwoman, featured prominently as a means of arousing fine feelings, as in Richardson, Sterne, and Henry Mackenzie. Similar currents developed within medicine and psychiatry, not least the movement towards ‘moral management’, taking the mad more seriously, and identifying them as a specialist branch of scientific understanding and treatment. These tendencies reached their height within the Romantic period, with madness being seen by Wordsworth, for example, as one danger of the heightened imagination, but also being valorised, as by Blake, as an exceptionally sensitive and privileged condition. This chapter analyses the major types of mental illness that dominated during the period and the ways in which they were discussed and represented.

Sociable conversation

SOCIABLE CONVERSATION, in all periods, but especially in the formal atmosphere and gender-restricted context of the eighteenth century, is the public face of the individual: that which is on display as against that which remains, more or less effectively, hidden from view. It represents the self that we wish to present to the world, even if that world is in the form of friends and family. The private self, certainly, can sometimes be observed through the cracks, and few performances are perfect, but to discover the extent and nature of that private self demands other sources, other more intimate means of inquiry, and other kinds of relationships. With writers like Johnson and Boswell we are unusually privileged, in that the opportunities are there for comparison between the self in performance and the self that can be read in their published and unpublished works. Thanks to Boswell, especially to his journal and his works on Johnson, we are afforded unique insights into both himself and his friend and idol Johnson, their inner selves as against their public and social personalities. In understanding these differences in perspective we can also read something of the nature of eighteenth-century society, of the weight given to social presence and performance and of the generally forbidden territory that was occupied by inner realities. This chapter explores some of those performances and some of that territory.

Samuel Johnson and James Boswell valued sociability as amongst the very highest pleasures of living within a civilised society. The whole business of interchange of ideas, of pleasantries, even of insults – in short, of what had become known in the period as clubbability – are conspicuously present in all accounts of the ways they chose to spend their time, both when together, during Boswell's usually annual visits to London, and in the course of their separate lives. Yet this straightforward truth also conceals personal complexities in each man's case that make their respective attitudes towards company, conversation and sociability a good deal more paradoxical. Much as they genuinely enjoyed sociable companionability, different, and sometimes overlapping, facets of their personalities at times pulled against their clubbable capacities: competitiveness, self-indulgence, depression and world-weariness were all essentially anti-social tendencies that either were in danger of damaging the civilised within society or by their very nature made isolating and self-absorbing demands on each man.

The long eighteenth century was the period in Britain and Western Europe when the mind came into its own. Thought – including progress in science and medicine and in the understanding of the mind itself – was at last, after the religious and civic turmoils of the seventeenth century, deriving the full benefit of those decisive breaks with the past that had occurred during the European Renaissance. Increasingly liberated from the remaining pockets of medievalism, such as humoral theory in understanding the body, and from strict religious oversight of what might be thought and written, scientists were able, probably for the first time, to give full rein to those fundamentals of modern science, free thought and factual observation. William Harvey, early in the seventeenth century, identified and demonstrated the circulation of the blood; Isaac Newton, half a century later, discovered the movements and orbits of lunar and planetary bodies. In the same way, the celebrated physician Thomas Willis argued in his Cerebri anatome (1664) that the human brain operated through a series of nervous impulses and reactions, basing his conclusions on clinical observation and experiment. The whole human organism was being recognized as more dynamic, more mechanical, and far more surprising than earlier generations of scientists had dared to think, and the most exciting faculty of all in the new body was the mind itself. There was more to thought, it began to appear, than we thought.

Philosophy and the mind

While some were observing the brain and the nervous system, other thinkers and medical men were turning their attention to issues concerning the mind – to what was being thought and why. Here the key figure was John Locke, the philosopher and physician. An Essay concerning Human Understanding (1690) was probably the single most influential philosophical work upon the study of mind for the century that followed (see chapter 33, “Philosophy”). By denying the existence of innate ideas and deriving all knowledge from sense or sensation, Locke separated thought from any residual traces of what might have been a divine template, and positioned it instead firmly within the individual organism, its species characteristics, and its distinctive quirks and malfunctions. In doing so, he set the agenda for attitudes towards issues of identity, of mental normality and abnormality, of popular as well as philosophical understanding of sanity and insanity, and of education for a chain of thinkers who followed.