Introduction
Disrupting a Definition

Everyone knows their own pain. How? This book explores the answer to this question historically, demonstrating the relationship between the pains people have known and the changing frameworks of philosophical, medical, religious, and scientific expertise that have claimed to know what pain is. It is, therefore, a contribution to current knowledge about the experience of pain, produced in a transdisciplinary space comprising perspectives from history, philosophy, anthropology, psychology, psychiatry, neuroscience, politics, art, and literary studies. Knowing Pain illuminates a history of painful experiences, a messy assemblage of many worlds of suffering, which disrupts commonplace appeals to the universality of pain. Here you will find: pain as specific, particular, mediated, and contingent; body-minds whose agonies are connected to the cultures they inhabit; brains that produce pain that makes sense only in and through the context of its experience; authorities that make and disseminate the situated concepts of pain, through which suffering is made meaningful; historical politics of the medical and moral valuation of pain; pains that count, and pains that are invalid. You will find claims that patients do not know their own pain at all and the provocation that your pain belongs to someone else's discrimination.

This book cuts against the grain of 'common sense' about the pain that people think they know. It documents well-known but under-appreciated phenomena, such as the history of extraordinary and devastating injuries that, nonetheless, did not hurt; the history of overwhelming suffering unconnected to any injury at all; the unreliability of the senses as either a signal for pain or a method of measuring pain; how these mutable senses, in combination with equally contingent emotional concepts, can change the experience of pain. It shows pain as a virtue and as a pleasure, and how much of the history of human pain has fallen beyond the ken or the interest of medicine. The world of medicine nevertheless plays a big part in the story, both in terms of the production of knowledge of what pain is and how to alleviate it, and concerning its role in creating limited definitions of pain that seemingly either overlooked or failed to treat a great tide of suffering. I delve into the lived experience of pain in all its physical, emotional, social, and cultural entanglements to reveal the kinds of apparently invisible pain that millions, nonetheless, have known and shared.

Aside from collating these phenomena, this book puts forward an original pain agenda. Ranging from antiquity to the present, and taking in pain knowledge and pain experiences from around the world, I draw upon the methodology of the history of the senses, the history of emotions, and the new history of experience to weave a narrative about the mutable patient, or the situated sufferer, often alone, sometimes in a collective.1 It is predicated on critical engagement with a strain of social neuroscientific and neurohistorical research that explains how the concepts by which humans express their experiences play a central role in the production of experiences. A history of pain concepts and pain practices becomes a history of the contextualized plastic, biocultural brain-body system. Pain, an embodied, embrained, but above all meaningful experience, is in and of the world. It may be something that almost every human has known, but there is nothing in the evidence of our own experience that affords us automatic insight into the pains of others, or into the pains of the past. To that end, this book is a sustained denial of universality, and a denial of easy recognition of the other in pain. I lay bare the difficulties and the politics of knowing pain - your own, someone or something else's - and the way that the experience of pain is mutable, historical, and unpredictable. I aim to show the connections between the construction, use, and experience of pain, understanding as a first principle that knowledge claims about pain occupy what pain is like.2

Definitions: A Contemporary Overview

Since one major purpose of this book is to historicize the experience of pain, to show that it can and does change over time, a necessary first step is to disrupt any operative definition that delimits what pain is. The formal definition of pain has focused the worlds of medicine and medical science on the kinds of pain research that are pursued and the kinds of pain that receive priority for treatment. Disrupting such definitions is essential if the varieties of pain experience, in the past and in the present, are to be recognized. In chapter 1, I will explore the historical formulations of pain, but I begin with the present and the possibilities current formal definitions afford.

The International Association for the Study of Pain (IASP) formulated a formal definition in 1979: 'Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.'3 Critics across the disciplines found this definition inadequate, and it was finally augmented and complicated (and improved) in July 2020. A series of qualifications and clarifications have been added. They make the formal definition less pithy and supply new possibilities for the study of pain, especially in historical terms:

• Pain is always a personal experience that is influenced to varying degrees by biological, psychological, and social factors.
• Pain and nociception are different phenomena. Pain cannot be inferred solely from activity in sensory neurons.
• Through their life experiences, individuals learn the concept of pain.
• A person's report of an experience as pain should be respected.
• Although pain usually serves an adaptive role, it may have adverse effects on function and social and psychological well-being.
• Verbal description is only one of several behaviors to express pain; inability to communicate does not negate the possibility that a human or a nonhuman animal experiences pain.4

The most welcome parts of this revision are as follows. First, the notion of pain as an objective phenomenon - something that can be mechanically measured or rated - is rejected in the first clause. Pain, it confirms, is subjective. Later, I'll explore the boundaries of this claim, showing that sometimes pain is not 'personal', but 'social', analysing the relational dynamics that colour the experience of both pain and relief. For now, it is helpful to think of pain in these terms, as different from person to person, and from time to time.

Second, the formal definition of pain has finally introduced a conceptual wedge between 'pain' and 'nociception'. The confusion, which is long-standing, and which has obfuscated scientific communication about how pain works, lies in the conceptual linkage of sensory perception with pain perception. Nociception, deriving from the Latin nocere, suggests that the nerve endings in the body that detect external stimuli - the cutting, burning, or compression of the skin, for example - are pain detectors. Those nerves then send 'pain signals' to the brain, which responds. This is based on an understanding of nocere as 'to hurt', when it might more usefully be translated as 'to damage'. Those nerves detect damage, and they send damage signals, but damage does not imply pain. Only when damage signals reach the brain does the brain produce pain, if the circumstances are right for such a production. By no means do all damage signals result in the experience of pain. The formal separation of pain and nociception is useful because it puts an end to the notion that pain is formally correlated with injury. I will return to this at much greater length.

The third qualification here is also useful but requires further revision. It is important to acknowledge that people learn what pain is: that it is not a simple human universal to which everyone has the same access; it is a complex human variable that is accessed in all manner of ways, according to place, time, and other intersectional criteria. The further implication attached to this conceptual learning process is that there is not one thing called 'pain', but many different pains, each according to the way in which life experiences unfold. I seek to understand what is precisely meant by the phrase 'life experiences', how they are formed, and how they might change over time.

Fourth, regarding subjective reporting of pain, this is an important step forward in wresting formal control of the definition, diagnosis, and treatment of pain from the hands of doctors and placing it instead in the hands of patients. The modern history of an objective science or measurement of pain is the history of either ignoring or amplifying subjective reporting of people in pain, and is revealing of the unseemly history of racism, misogyny, classism, and ageism within the medical and allied professions. It should be enough for the medical establishment to endorse subjective reports of pain as truthful accounts of the experience of pain. As this book will illustrate, this has not typically been the case.

The word 'usually' in the fifth qualification could be struck because it is counterproductive. It is widely acknowledged that one of the biggest...