The Channel of Synthesis joins the Root centre to the Solar Plexus centre through Gates 19 and 49, and both of those numbers are borrowed. They are positions in the King Wen sequence of the I Ching, the Chinese divinatory classic whose sixty-four hexagrams Human Design maps one to one onto the sixty-four gates of its bodygraph. Read as I Ching rather than as Human Design, the two numbers name two independent oracle texts.
Hexagram 19, Approach (Lin). The earth bending over the lake. It is the approach of the great, a springtime advance that succeeds joyfully yet must reckon with the turn of the year.
Hexagram 49, Revolution (Ge). Fire in the lake, two elements that annul each other. Its image is the molting of an animal's coat, and its judgment is that radical change is believed only on its own day.
The I Ching itself never sets these two hexagrams in a pair. Each stands alone in the sequence, consulted about a changing situation and answered in counsel that passes. The pairing is a construction of Ra Uru Hu's system, published from 1987, which fixes each hexagram to a position in a birth chart and reads the joined pair as a lasting trait of the person. The correspondence of number is real, and both hexagrams can be followed into their own entries in this atlas; the pairing, and the character read out of it, belong to the modern system alone.