Part I, Chapter 4: Of Ideas of Things and Signs
WHEN we consider an object in itself, and in its own nature, without extending the view of the mind to that which it may represent, the idea we have of it is the idea of a thing, as of the earth, of the sun; but when we regard a certain object only as representing another, the idea which we have of it is the idea of a sign. It is in this way that we commonly regard maps and pictures. Thus the sign contains two ideas, one of the thing which represents, the other of the thing represented, and its nature consists in exciting the second by means of the first.
Various divisions of signs may be made, but we shall content ourselves here with three, which are of the greatest importance.
I. There are some signs which are sure, which are called in Greek tekmeria, such as respiration of the life of animals; and there are others which are only probable, and which are called in Greek, semeia, as paleness is only a probable sign of the pregnancy of women.
The majority of rash judgments arise from our confounding these two kinds of signs, and from our attributing an effect to a given cause, when it may spring equally well from other causes, and is thus only a probable sign of that cause.
II. There are signs which are connected with things, as the expression of the countenance, which is a sign of the emotions of the mind, is connected with those emotions which it expresses; symptoms which are the sign of disease are connected with those diseases; and, to have recourse to higher examples, as the ark, a sign of the church, was connected with Noah and his children, who were the true church of that time. Thus our material temples, which are signs of the faithful, are often connected with the faithful. Thus the dove, the image of the Holy Spirit, was connected with the Holy Spirit. Thus, too, the water of baptism, which is the figure of spiritual regeneration, is connected with that regeneration.
There are also signs which are separated from things, as the sacrifices of the ancient law, which are signs of the offering of Christ Jesus, were separated from that which they represented.
This division of signs enables us to establish the following maxims: —
1. That we are never able to reason certainly either from the presence of the sign to the presence of the thing signified, since they are signs of things which are absent; or from the presence of the sign to the absence of the thing signified, since they are signs of things which are present. It is, therefore, by its own nature that the sign must be judged.
2. That though a thing in one state cannot be a sign of itself in the same state, since every sign requires a distinction between the thing representing, and that which is represented, it is nevertheless very possible that a thing in a certain state may represent itself in another state; as it is very possible that a man in his chamber may represent himself preaching; and that thus the only distinction necessary between the thing signifying, and the thing signified, is that of state:—that is to say, that a thing may be in one state a thing signifying, and in another a thing signified.
3. That it is very possible that one thing may hide and reveal another thing at the same time, and that thus those who have said that nothing is made manifest by that which hides it, have advanced a maxim far from true; for since the same thing may be at the same time both a thing and a sign, it may obscure, as a thing, that which it reveals as a sign; thus the warm ashes hide the fire as a thing, and reveal it as a sign; thus the forms assumed by angels hide them as things, and reveal them as signs; thus the eucharistic emblems hide the body of Jesus Christ as a thing, while they reveal it as a symbol.
4. We may conclude that since the nature of the sign consists in exciting in the sense by means of the idea of the thing signifying, that of the thing signified, that so long as that effect remains—that is to say, so long as that double idea is excited—the sign remains, even though the thing in its proper nature be destroyed. Thus it matters not whether the colours of the rainbow which God has taken as a sign that he would no more destroy the human race by a flood, be true and real, provided that our senses always receive the same impression, and that we are enabled by this impression to realise God’s promise; in the same way it matters not whether the bread of the Eucharist remains in its proper nature, provided that it always excites in our sense the image of that bread which enables us to conceive in what way the body of Jesus Christ is the nourishment of our souls, and how the faithful are united to each other.
III. The third division of signs is that of natural ones, which do not depend on the fancies of men, as an image which appears in a mirror is a natural sign of that which it represents; and of others which exist only from institution and establishment, and which have only a distant relation to the thing signified, or it may be, none at all. Thus words are by institution the signs of thought, and characters of words. We shall explain, in treating of propositions, an important truth in relation to these kinds of signs, to wit, that we are able on some occasions to affirm the thing signified.