Also called: Benham's central principle · Adapt the line to the subject

Where on the hand: A governing rule applied to every mark and line on any hand, at the moment of interpretation rather than at any location.

What it looks like: Nothing visible; it is the instruction that the same mark drawn identically on two different hands is not the same reading.

Benham's central principle: the meaning of any line must be adapted to the whole hand it sits on — its texture, colour, thickness and refinement — rather than read off a fixed table. The identical Girdle of Venus on a coarse, thick, red hand and on a fine, pale, sensitive hand means two different things.

Read with care: “Adapt the line to the subject, not the subject to the line” is not found anywhere in Benham. Searched Part Second chs. I–III in full plus exact-phrase web search. It appears to be a modern maxim that acquired a Benham byline. The principle itself is sound and widely held; the attribution is not.