From Emmanuel Carrère's fine biography of Philip K. Dick, I am Alive and you are Dead – “A powerful novelistic magic informs those places that lack witnesses. And I feel there is a profound though generally unremarked inequality between those who can avail themselves of this luxury of being able to live for a week or six months unseen by anyone but absolute strangers – which is tantamount to not being seen at all – and those whom the constraints and obligations of their lives force to remain permanently under the gaze of those who know them.”
From Susan Bell's The Artful Edit – “Collaboration is generally unnatural to writers – most would put solitude ahead of cash if asked to choose between the two.”
Which is a way of putting non-survival ahead of survival.
From Don DeLillo's White Noise – “There must be something in family life that generates factual error. Overcloseness, the noise and heat of being. Perhaps something even deeper, like the need to survive.”
Error and survival are bound together -- to think clearly or novelistically, it's necessary to wander dangerously far from the Group. From a "Wall Street Journal" interview with Cormac McCarthy –
“WSJ: But is there something compelling about the collaborative process compared to the solitary job of writing?
CMC: Yes, it would compel you to avoid it at all costs.”
These costs are however high. And the writer only gets to enjoy so many hours of hard-won productive solitude before solitude transforms into loneliness, which is no use to anyone.