Errors

In this chapter and in the following three, we shall treat of those four things which we have just said are confused and taken for a simple sensation; and we shall explain only, in general, the errors into which we fall: because if we wished to enter into detail, it would never be finished. We hope, however, to put the reader’s mind in a position to discover with very great ease all the errors into which the senses can lead us; but we ask of them, for this purpose, that they meditate with some application, both on the following chapters and on the one they have just read.

On the error we commit concerning the action of objects against the external fibres of our senses

The first of these things that we confuse in each of our sensations is the action of objects upon the external fibres of our body. It is certain that one almost never makes a distinction between the soul’s sensation and this action of objects, and this needs no proof. Almost all men imagine that the heat, for example, which one feels, is in the fire that causes it, that light is in the air, and that colours are upon coloured objects. They do not think of the movements of imperceptible bodies that cause these feelings, or rather that accompany them.

Cause of this error

It is true that they do not judge that the pain is in the needle that pricks them, in the same way that they judge that heat is in the fire; but this is because the needle and its action are visible, whereas the tiny parts of the wood that come out of the fire and their movement against our hands are not seen. Thus, seeing nothing that strikes our hands when we warm ourselves, and feeling heat there, we naturally judge that this heat is in the fire, for lack of seeing anything else there.

So that it is ordinarily true that we attribute our sensations to objects, when the causes of these sensations are unknown to us; and because pain and tickling are produced by sensible bodies, such as a needle and a feather that we see and touch, we do not on that account judge that there is anything resembling these feelings in the objects that cause them.

Objection and reply

We do not fail to judge that the burn is not in the fire, but only in the hand, although it has for its cause the tiny parts of the wood just as heat does, which we nevertheless attribute to the fire: but the reason for this is that the burn is a kind of pain; for having judged several times that pain is not in the external body that causes it, we are led to make the same judgment about the burn.

What also leads us to judge in this way is that pain or the burn strongly applies our soul to the parts of our body, and this turns us away from thinking of anything else. Thus the mind attaches the sensation of the burn to the object that is most present to it; and because we recognize shortly afterwards that the burn has left some visible marks on the part where we felt the pain, this confirms us in the judgment we have made that the burn is in the hand. But this does not prevent us from receiving this general rule: that we are accustomed to attribute our sensations to objects, whenever they act upon us through the movement of some invisible parts; and it is for this reason that one ordinarily believes that colours, light, odours, flavours, sound, and some other feelings, are in the air or in the external objects that cause them, because all these sensations are produced in us by the movement of some imperceptible bodies.