"...People often say that a set of books looks ugly if all volumes are not in the same format, but I was impressed to hear the Abbot Kōyū say, 'It is typical of the unintelligent man to insist on assembling complete sets of everything. Imperfect sets are better.'
In everything, no matter what it may be, uniformity is undesirable. Leaving something incomplete makes it interesting, and gives one the feeling that there is room for growth. Someone once told me, 'Even when building the imperial palace, they always leave one place unfinished.' In both Buddhist and Confucian writings of the philosophers of former times, there are also many missing chapters."
-- written by the Buddhist priest Kenkō, appearing in Essays in Idleness: the Tsurezuregusa of Kenkō, translated by Donald Keene.