Water and fire magnify this. The hardest part of translation is tone. Section 1 (“茶者南方之嘉木也一尺二尺乃至数十尺其巴山峡川”) is the nearby evidence: The opening judgment cannot be softened with “perhaps”; doing so removes Lu Yu’s certainty. This treats the text as a testable judgment, not a slogan.
Half a cup is water.