Yijing · the Book of Changes · 易經

Older than Taoism and adopted by it: an oracle of sixty-four hexagrams, each a stack of six lines that are either broken (yin) or solid (yang). Two marks, six places, and the whole field of change unfolds — 2⁶ = 64 situations, each shading into the next as a single line turns. Leibniz, shown the arrangement in 1703, recognized his own binary arithmetic in it and was amazed. The rhyme with the Tree is exact in structure: the Sefer Yetzirah builds all that exists from twenty-two letters "engraved, hewn, weighed, and combined" — 231 gates from the pairs — the same conviction that a cosmos can be spelled out of a tiny alphabet of marks. Both are combinatorial creations; one reads the code to divine, the other to bless.