Loneliness - the sense of isolation, accompanied by the feeling of alienation - has always been a feature of the human condition.
References to the unhappy state of loneliness are scattered throughout the Bible. As the 17th-century poet John Milton reminded us: "Loneliness is the first thing which God's eye named not good."
However, it was only in the early modern era that people started talking about loneliness as a standalone problem. Until the 19th century, loneliness tended to be associated with the physical state of being apart from society or company.
During the 19th century, loneliness became associated with people's inner state, and philosophers such as Soren Kierkegaard were preoccupied with the fear of loneliness.
Until the 21st century, loneliness was principally a problem addressed by theologians, philosophers, sociologists, poets and artists.
In recent times, it has become an issue for health professionals.
No doubt there are millions of us who feel lonely. It is impossible to determine with any degree of accuracy whether people are more lonely than in previous times. We certainly talk a lot more about it. But the feeling and the emotions associated with loneliness cannot be reduced to measurable quantities.
Unfortunately, once a dimension of the human condition becomes framed in the language of medicine, it is only a matter of time before it acquires the status of an epidemic. Inevitably, health professionals in the United States have sounded the alarm on the loneliness epidemic .
Loneliness is the fashionable new problem in the United Kingdom. Earlier this year, the UK government appointed Ms Tracey Crouch into the newly established post of minister for loneliness. The appointment follows a series of alarming reports about the prevalence of loneliness among elderly people; this month, the problem expanded to include young people.
The Office for National Statistics reported that "young adults are more likely to feel lonely than older age groups". Earlier this week, a study claimed that "lonely millennials" faced a variety of health and social problem .
No doubt there are millions of us who feel lonely. It is impossible to determine with any degree of accuracy whether people are more lonely than in previous times.
We certainly talk a lot more about it. But the feeling and the emotions associated with loneliness cannot be reduced to measurable quantities.
So when campaigners assert that loneliness is a "comparable risk factor for early death as smoking 15 cigarettes a day, and is worse for us than well-known risk factors such as obesity and physical inactivity", they speak as propagandists rather than as scientists.
Campaigners who warn that "loneliness increases the likelihood of mortality by 26 per cent" turn an intangible feature of our inner life into calculable quantities.
The medicalisation of loneliness mystifies a condition for which there is no cure. Loneliness often expresses the difficulty that we have in understanding our place in the world.
When people struggle to come to terms with their self and find it difficult to gain affirmation, loneliness can assume the form of an existential crisis.
The philosopher Hannah Arendt described loneliness as "that nightmare which, we all know, can very well overcome us in the midst of a crowd" when we feel "deserted by oneself". She argued that this nightmare is a symptom of the difficulty we have in engaging with ourselves.
She believed that the destructive effects of loneliness could be contained through the habit of conversing with oneself. She called this "silent dialogue of myself with myself" solitude.
For her, solitude had a positive connotation. She wrote that "though alone, I am together with somebody (myself) that is". Her attempt to convert loneliness through an inner dialogue into solitude offers one way of coming to terms with our estrangement from ourselves.
Others, such as the writer Maya Angelou, found refuge in music. "I could crawl into the space between the notes and curl my back to loneliness", she wrote.
Still others, such as the existentialist feminist writer Simone de Beauvoir, embraced loneliness and sought to harness its creative force.
What they all understood was that we can exist with loneliness through finding value in our solitude. Meaning, rather than a cure, helps us deal with the problems of existence.