Here is what seems like a paradox: the practice of solitude tends to improve rather than impair a person's capacity for genuine relationship.
The psychoanalyst Donald Winnicott described the capacity to be alone as among the most important developmental achievements of early childhood. Paradoxically, it is first learned in the presence of a trusted caregiver: the child learns to play alone, absorbed in their own experience, while the parent is present but not intrusive. The child develops an interior space, a capacity for self-directed experience, that does not require the other's constant validation. Winnicott argued that this capacity is the foundation for all mature intimacy: only someone who has a genuine interior life to share can truly share themselves with another person. A person who cannot be alone will fill their relationships with distraction and performance rather than genuine contact.
The philosopher and theologian Paul Tillich made a similar distinction: "Language has created the word 'loneliness' to express the pain of being alone, and the word 'solitude' to express the glory of being alone." The difference is not circumstantial but attitudinal. It depends on whether you bring a self to the aloneness or not.
Rollo May, in The Courage to Create (1975), argued that creative work requires what he calls the encounter with the daimonic: the confrontation with one's own depths, including the parts that are frightening or destructive. This confrontation cannot happen in social space, because social space requires the performance of a manageable self. The artist, the thinker, the serious meditator, the therapist processing their own material: all of them periodically require a withdrawal from social life into a space where the performance can stop and the real confrontation can begin.
There is also a practical point about cognitive load that cognitive science has largely confirmed. Attention is a limited resource, and social interaction is one of its most demanding consumers. Tracking social cues, managing others' emotional states, responding to conversational demands in real time: these are genuinely taxing activities. Sustained creative or philosophical work requires a quality of attention that is difficult to maintain while simultaneously managing social presence. This is not a bug; it's a feature of brains that are deeply wired for social interaction. It means, practically, that if you want to think hard about something, you need to get away from people for a while.
None of this is an argument for hermitage or misanthropy. It is an argument for what we might call the rhythm of contact and withdrawal: periods of genuine social engagement alternating with periods of genuine solitude. The contemplative traditions figured this out millennia ago. Modern work culture, with its addiction to constant availability and its suspicion of anyone who closes their door, has largely forgotten it.