Part One · The Measure · Getting the Ruler Right First

This book walks the four stations of the śrāvaka path: sotāpanna, sakadāgāmin, anāgāmin, arahant—the stream-enterer, the once-returner, the non-returner, and the one in whom the defilements are forever exhausted. The road is not long, but each station lies deeper than the last; and before setting out, one thing must be settled first: the ruler by which progress is measured.

Most people measure practice by experience—how deep the absorption, how bright the light, how lofty the state. But when the canon defines the fruits, it uses another ruler, and only this one: which fetters have been severed. What it counts is what is gone, not what is gained.

The two chapters of Part One settle exactly this. Chapter one exchanges the ruler: we read the Buddha's own defining words, and we watch the case of the wisdom-liberated monks in the Bamboo Grove, until it is clear why a fruit is a subtraction. Chapter two reads the ruler's markings: every fruit has two faces, approach and fruit—coming down, and down for good; the four pairs and eight persons are the joints of this subtraction.

Read these two chapters, and the way to walk the four stations ahead is already held in this one ruler and this one pair of terms. Get the ruler right first, and the road runs straight. We begin with chapter one.