Middle

The middle finger is the finger of Saturn, named for the Mount of Saturn beneath it, and the naming carries the planet's whole character with it. Saturn in astrology signifies limit, weight, time, duty and the things that do not come easily, and the tradition reads the middle finger for exactly those: seriousness, caution, prudence and a sense of responsibility, turning in the unfavourable reading into gloom, suspicion and a narrow spirit. A finger leaning toward Jupiter is read as ambition tempered; one leaning toward Apollo, as gravity lightened.

The Saturnian vocabulary spreads further here than at any other digit. The fate line, which runs up the middle of the palm toward this finger, is called the line of Saturn for no reason except where it is headed, and Cheiro treats the two together under one heading. That is the tell of a borrowed system: the line is named after the mount, the mount after the planet, the finger after the mount, and at no point in the chain does anything about the hand enter.

It is the longest digit, which the tradition takes as fitting for the element it says governs the rest, and it is also the digit whose relative length varies least from hand to hand, so the feature carrying the heaviest reading is the one with the least to distinguish it. The reading is a traditional interpretive practice, and it has not been shown to correspond to anything about the person whose hand it is.

Sources Introductiones apotelesmaticae elegantes in chyromantiam, physiognomiam, astrologiam naturalem, complexiones hominum, naturas planetarumJohannes ab Indagine (Johannes Rosenbach) with Palmistry for AllCheiro (William John Warner)

Here the two elemental schemes are furthest apart. Japanese esoteric Buddhism makes the middle finger fire, ka, the third of the five elements counted inward from the little finger and the one at the centre of the hand. The yogic hasta mudras make it ether, akasha, the subtlest of the five and the one the others are said to arise within. Fire and ether are not neighbours in either cosmology, so this is not a small slippage in a shared list. It is evidence that the two schemes were built independently and that neither is derived from the other.

Both do agree in giving the central finger a distinguished element rather than an ordinary one, and that is probably the anatomy speaking. The middle finger is the longest and the most nearly axial: the hand closes around it, the other digits fold toward it, and a fist is built on it. A scheme that assigns five elements to five fingers has to decide what the middle of a hand is, and both of these decided it was something central rather than something common.

Its best known modern use is an insult, and the gesture is old, attested in the Roman world long before either elemental scheme reached the form it now has. That is worth stating plainly beside the ritual material, because a finger can carry a sacred meaning in one tradition and an obscene one in another without either being a corruption of the other.

Sources Mudra: A Study of Symbolic Gestures in Japanese Buddhist SculptureE. Dale Saunders with Asana Pranayama Mudra BandhaSwami Satyananda Saraswati