“It is unsurprising that social isolation or loneliness have been strongly associated with depression,18 suicide,19 anxiety,20 insomnia,21 fear and the perception of threat.22 It’s more surprising to discover the range of physical illnesses that they can cause or exacerbate. Dementia,23 altered brain function,24 high blood pressure, heart disease and strokes,25 lowered resistance to viruses,26 even accidents,27 are all more common among chronically lonely people. One study suggests that loneliness has a comparable impact on physical health to smoking fifteen cigarettes a day.28 The doctrine has also helped to create what some people describe as a spiritual void: when human life is conceived as a series of transactions, when relationships are recast in purely functional terms, when personal gain counts for everything and pro-social values for nothing, the sense of meaning and purpose is sucked from our lives. We find ourselves in a state of alienation, of anomie, an experience of dislocation that extends beyond the more immediate determinants of mental health. Our psychological and economic welfare depends on our connection with others. Of all the fantasies human beings entertain, the idea that we can go it alone is the most absurd, and perhaps the most dangerous. We stand together or we fall apart.”