If the feeling of twoness or of oneness is anything but an inference, why is it that a person can perceive two objects on two fingers which are some distance apart, but perceives the same two objects as one when the fingers are brought near together and touched in the same way?  It is difficult to see how bringing the fingers together could make a sensation any less complex, but it would naturally lead a person to infer one object, because of his previous associations.  He has learned to call that one which seems to occupy one place.  If two contacts are made in succession he will perceive them as two because they are separated for him by the time interval and he can perceive that they occupy different places.

When two exactly similar contacts are given and are perceived as one, we cannot be sure whether the subject feels only one of the contacts and does not feel the other at all, or feels both contacts and thinks they are in the same place, which is only another way of saying he feels both as one.  It is true that when asked to locate the point he often locates it between the two points actually touched, but even this he might do if he felt but one of the points.  To test the matter of errors of localization I have made a few experiments in the Columbia University laboratory.  In order to be sure that the subject felt both contacts I took two brass rods about four inches long, sharpened one end and rounded off the other.  The subject sat with the palm of his right hand on the back of his left and his fingers interlaced.  I stimulated the back of his fingers on the second phalanges with the sharp end of one rod and the blunt end of the other and asked him to tell whether the sharp point was to the right or to the left of the other.  I will not give the results in detail here, but only wish to mention a few things for the purpose of illustrating the point in question.  Many of the answers were wrong.  Frequently the subject would say both were on the same finger, when really they were on fingers of opposite hands, which, however, in this position were adjacent fingers.  Sometimes when this happened I would ask him which finger they were on, and after he had answered I would leave the point on the finger on which he said both points were and move the other point over to the same finger, then move it back to its original position, then again over to the finger on which the other point was resting, and so on, several times.  The subject would tell me that I was raising one point and putting it down again in the same place all of the time.  Often a subject would tell me he felt both points on the same finger, but that he could not tell to which hand the finger belonged.  When two or more fingers intervened between the fingers touched no subject ever had any difficulty in telling which was the sharp and which the blunt point, but when adjacent fingers were touched it was very common for the subject to say he could not tell which was which.  This cannot