illusions of thought are quite as possible as illusions of the senses, though rarer for the reasons above stated. But the question of frequency has no theoretical importance.
I have shown elsewhere, by experiments on hysterics, that it is possible by the intermediary of their insensibility to touch to suggest ideas on the value of which the patients make mistakes. For instance, you take the finger in which they have no sensation, you touch it, you bend it. The patient, not seeing what is done, does not feel it, but the tactile sensation unfelt by their principal consciousness somehow awakes the visual image of the finger; this enters into the field of consciousness, and most often is not recognised by the subject, who describes the occurrence in his own way; he claims, for instance, that he thinks of sticks or of columns. In reality he does not know of what he is thinking, and we know better than he. He is thinking of his finger, and does not recognise it.
All these examples show that the clearly defined characteristics into which it is sought to divide extrospection and introspection do not exist. There is, however, a reason for preserving the distinction, because it presents a real interest for the psychology of the individual. These two words introspection and extrospection admirably convey the difference in the manner of thinking
