Until about five years ago, I would hesitate to buy books if I had other, unfinished books that I was currently reading. It seemed irresponsible to “start on something new” without finishing things that were in progress. This is the kind of attitude that leads you to visit every single room and see every single exhibit in a museum, exhausting yourself (thus precluding visits to other museums for a while). In retrospect, this was an unwise approach.
Umberto Eco (I learn via Nassim Taleb), and others before him, advocates the notion of an antilibrary. Books that one has not read are clearly more valuable than books that one has read. So simple, and so obvious. One should fill one’s shelves with unread books.
Of course this does not mean indiscriminate acquisition, though. We should curate, buy books on the basis of potential value – at present or at some time in the future. Look for links between books, associations, counterpoints, juxtapositions. Thus we build a space – both literary and physical – that is instantly accessible, offering up its riches. We can immediately jump from book to book, trace connections and make new ones, a quadratically increasing number of potential contrasts…
Talking to a new acquaintance for ten hours does not hold ten times as much “utility” or interest as talking to him or her for one hour. Trying to exhaust or deplete one person before moving on to make another acquaintance would be rude, clumsy, pointless and tiring. Although we may sometimes wish to converse with someone for days or weeks immediately upon meeting them, sometimes a few minutes is enough to have a crucial insight.
A metaphor, and an obvious insight now, but one that bears repetition. Finally: it is important that the collection is physical, concrete shelves with physical volume and mass. No digital interfaces, however convenient, can make up for the lack of physicality. They are complementary at best.