Week 8: The I Ching

A 3,000-year-old divination system built on genuinely random coin tosses — and the case that structured randomness can produce advice worth taking.

The I Ching (“Book of Changes”) is one of the oldest continuously used divination systems in the world, built on a genuinely elegant piece of engineering: a physical randomising procedure (traditionally, tossing three coins six times, or manipulating yarrow stalks) that selects one of 64 hexagrams, each attached to a fixed body of interpretive text refined over centuries of commentary. Unlike a horoscope or a tarot reading, the random process here is mechanically real — there is no sleight of hand in how the hexagram is chosen.

That makes the I Ching the cleanest case this course can offer for a genuinely interesting question: if the randomising step is legitimate, does that make the reading legitimate too? The activity below builds a deliberately simplified version — one random draw from five lines, with the mechanism shown rather than hidden — so you can test your own reaction to a system that is provably fair, in a way tarot and astrology are not.

Two things are worth separating. First, the coin toss is real randomness: no information about your specific situation enters the system at any point. Second, the reading of the result is where all the interpretive weight is actually carried — a centuries-refined hexagram text, or five short lines written for a demo, still needs a human to map it onto their actual problem. That mapping is a real cognitive act, often a useful one, and entirely independent of whether the coin toss “knew” anything.

What a hexagram actually is#

The structure is precise enough to state exactly. A hexagram is a stack of six lines, each either broken (yin) or unbroken (yang), built from two three-line trigrams stacked on top of each other. Six binary positions give exactly 2⁶ = 64 possible hexagrams, each attached to its own name and text — Qian (“The Creative”), Kun (“The Receptive”), and 62 others. The historical casting methods generate exactly this kind of structured randomness: the yarrow-stalk method (dividing and counting a bundle of 49 stalks through several rounds) or the simpler three-coin method (heads/tails patterns mapped onto broken/unbroken lines) both produce one of 64 fair, equally derivable outcomes, line by line, with moving lines that can shift one hexagram into another.

A text refined for two thousand years, not read once and left#

Unlike a tarot deck’s individually authored cards, the I Ching’s 64 hexagram texts sit inside a much larger, cumulative body of commentary called the Ten Wings, traditionally associated with Confucius and built up over centuries by successive scholars annotating and re-interpreting the base text. The I Ching is one of the Confucian Five Classics — a core text studied by scholars, officials and statesmen across Chinese history, closer in social standing to a foundational philosophical text than to a fortune- teller’s booth. Reducing it to “Chinese fortune telling” erases both the philosophical weight of that commentary tradition and the fact that its use was overwhelmingly about ethical reflection on a situation, not literal prophecy. The single most influential entry point for Western readers is sinologist Richard Wilhelm’s 1923 German translation, later rendered into English by Cary F. Baynes (1950) — and that English edition opens with a foreword by a familiar name.

Set beside week 6 and week 7, the I Ching is the structural outlier: astrology reads a birth chart (a fixed, closed data point) and tarot reads an open, individually chosen symbol set — but the I Ching pairs a demonstrably fair randomiser with a closed, centuries-refined commentary text, which is why this week’s activity can show you the mechanism directly rather than asking you to take the fairness of the process on faith.

Further reading#

• The I Ching, or Book of Changes, trans. Richard Wilhelm & Cary F. Baynes, foreword by C. G. Jung (Bollingen edition, 1950).

Cast, then read the mechanism#

Ask a real question, then cast. Read “How this works” before you decide what you think of the answer you got.