The evil eye is a practical belief rather than a doctrinal one. It holds that a look, often an admiring one and often unintentional, can damage what it falls on: a child, a herd, a new house, a run of good luck. Around the Mediterranean the counter-measures are numerous and cheap, and the khamsa is among the most durable. It works by the number and the gesture together. Five is the operative quantity, the hand is thrown open towards the threat, and in speech the same defence appears as a formula built on the word for five, sometimes used the moment a compliment has been paid.
The object follows from the gesture. A silver pendant on a chain keeps the hand permanently raised on behalf of the wearer; a hand hung by the door does the same for the household; a hand moulded into a wall, painted over a gate or worked into the back of a mirror extends the protection to the building. Regional workshops give the form its variety, with filigree, granulation, inset stones, fish, eyes and Hebrew or Arabic inscriptions worked into the palm. In North African silverwork the khamsa sits within a much larger repertoire of protective jewellery, and it is frequently combined with other defences rather than used alone, which is a good indication that nobody treated it as sufficient by itself.