There has been much discussion on the question whether gesture signs were originally invented, in the strict sense of that term, or whether they result from a natural connection between them and the ideas represented by them, that is whether they are conventional or instinctive. Cardinal Wiseman (Essays, III, 537) thinks that they are of both characters; but referring particularly to the Italian signs and the proper mode of discovering their meaning, observes that they are used primarily with words and from the usual accompaniment of certain phrases. “For these the gestures become substitutes, and then by association express all their meaning, even when used alone.” This would be the process only where systematic gestures had never prevailed or had been so disused as to be forgotten, and were adopted after elaborate oral phrases and traditional oral expressions had become common. In other parts of this paper it is suggested that conventionality chiefly consists in abbreviation, and that signs are originally self-interpreting, independent of words, and therefore in a certain sense instinctive.
Another form of the above query, having the same intent, is whether signs are arbitrary or natural. The answer will depend upon what the observer considers to be natural to himself. A common sign among both deaf-mutes and Indians for woman consists in designating the arrangement of the hair, but such a represented arrangement of hair familiar to the gesturer as had never been seen by the person addressed would not seem “natural” to the latter. It would be classed as arbitrary, and could not be understood without context or explanation, indeed without translation such as is required from foreign oral speech. Signs most naturally, that is, appropriately, expressing a conception of the thing signified, are first adopted and afterwards modified by circumstances of environment, so as to appear, without full understanding, conventional and arbitrary, yet they are as truly “natural” as the signs for hearing, seeing, eating, and drinking, which continue all over the world as they were first formed because there is no change in those operations.